a pre-loved toy marketplace for families
PROJECT OVERVIEW
What this app does
A marketplace for around 10,000 users to buy and sell pre-loved toys with listing and profile pictures. Sellers can submit verification details, buyers can leave star ratings after completed purchases, and payments are held in escrow until the buyer marks delivery as complete.
As an anonymous visitor, I can browse available pre-loved toys and view listing details
As a seller, I can view purchased listings and mark an order as shipped
As an administrator, I can review seller verification requests and record a decision
As a buyer, I can browse available toys and view seller information and ratings
As a buyer, I can add or update my profile picture
As a buyer, I can purchase an available toy with payment held in escrow
As a buyer, I can view my purchases and mark an order as delivered
As a buyer, I can leave a star rating after a completed purchase
As a seller, I can add or update my profile picture
As a seller, I can publish a pre-loved toy listing with multiple pictures
As a seller, I can submit a verification request and view its status
The following user counts are projected totals after one year of growth
50
administrators
Internal operations staff who review seller verification requests.
2950
sellers
Registered members whose primary activity is publishing toys, completing verification, and fulfilling orders.
7000
buyers
Registered members whose primary activity is discovering and purchasing toys.
1000
anonymous_visitors
Unregistered visitors who can browse available toys and seller information but cannot purchase or publish.
COST BREAKDOWN
How your requirements become a plan and a price
Momen doesn't give a vague quote: it first sizes the project's actual demand for each capability and resource, then costs each item out. The numbers in the 'Project demand' column below — their scale assumptions and derivations — are detailed in Scale & sizing
Minimum viable plan
PRO
Escrow-backed toy purchases require payment capabilities available in the PRO plan.
See the capability-by-capability assessment ▾
PROJECT DEMAND
ALLOWANCE PROVIDED (COMPOSITION)
AI points add-on
x 0
0 points
not purchased
(plan/kit 5.0M points)
No requirement
$ 0
Outbound data transfer add-on
x 26
1.09 TB/mo
500GB × 26/year, amortized monthly
(plan/kit 10.00 GB/mo + add-on +1.08 TB/mo)
Add-on fills +1.08 TB/mo gap beyond plan/kit
$ 75.83
Object storage
add-on
x 1
24.11 GB
100GB × 1/year, amortized monthly
(plan/kit 10.00 GB + add-on +14.11 GB)
Add-on fills +14.11 GB gap beyond plan/kit
$ 2.92
Database storage add-on
x 0
843.74 MB
not purchased
(plan/kit 1.00 GB)
Covered by plan/kit (margin ~19%)
$ 0
single-tenant kit
x 0
2 req/s
not purchased
(plan/kit 25 req/s)
Covered by plan/kit (margin ~1150%)
$ 0
PRO
x 1
Pro is the minimum viable plan
Pro
(Plan tier: PRO)
See minimum viable plan above
$ 99
plan + add-ons · usage-based · no development cost
WHY MOMEN
Your options for this project
In the table below, the 'monthly infrastructure' for the self-built / AI routes is derived from the AWS list prices shown below, sized against this project's actual usage. Figures cover infrastructure and operations only — AI usage is billed separately and excluded here, so they don't match the $177.75/mo all-in above.
Current usage sizing
AWS list pricing
525.13 GB (first 100GB free)
Internet egress → 47.26
24.11 GB-month
S3 Standard → 0.55
0.84 GB-month
RDS gp3 storage → 0.1
2 × db.m6g.large (Multi-AZ) × 730h
RDS PostgreSQL db.m6g.large → 232.14
2 × t4g.large × 730h
EC2 t4g.large → 98.11
Total ≈ $378.17 / mo
Pure cloud resources
DEVELOPMENT COST
MONTHLY CLOUD INFRA ($/MO)
MONTHLY TOTAL (INFRA + OPS, EXCL. AI USAGE)
Traditional outsourcing / build in-house
about $130,000 - $175,000
≈ $378
Based on the AWS estimate above
≈ $2,378
Infra $378 + ops ~$2,000
4-6 months
5 / 5
Vibe Coding
about $20,000 - $27,000
≈ $378
Based on the AWS estimate above
≈ $1,878
Infra $378 + ops ~$1,500
hours
5 / 5
AI full-stack generation
about $9,000 - $11,500
≈ $378
Based on the AWS estimate above
≈ $1,878
Infra $378 + ops ~$1,500
hours
3 / 5
Off-the-shelf SaaS / vertical solution
$0
N/A
Priced per seat, not by cloud infra
≈ $16,000+
Per-seat pricing, tens of thousands of users
days
1 / 5
Momen
Recommended
$0
$178
All-in: egress / storage / auto-scaling; excludes AI usage
$178
hours
5 / 5
Servers, databases, traffic and storage are inherent infrastructure costs for this project — you pay them whether you outsource, use Cursor or Lovable, or build it yourself (self-built runs ≈ $378.17/mo at AWS list prices, often more), on top of the dev and ops staff you'd need to hire. Momen bundles all of it into $0/mo all-in and removes the need for an ops team.
The frontend can be generated with AI tools (Cursor, Lovable, etc.); the hard part is the backend — auth, database, scaling, data security and ops. Momen delivers a production-grade backend as a BaaS: keep the vibe-coding speed on the frontend, while the backend runs on proven infrastructure — reliable, with no self-hosting or ops.
SCALE & SIZING
What scale this estimate assumes, and how the numbers are derived
Cost depends heavily on usage volume. First see the key assumptions and business scenarios this estimate uses, then the full calculation derived from each scenario for every resource — all adjustable to your real situation
We assume 10,000 registered accounts because the requirement explicitly states a user base of around 10,000, which takes priority over a generic marketplace benchmark. The population is partitioned by each account's primary access role, while anonymous browsing is tracked separately; if buyers and sellers must hold simultaneous roles, the role model can be adjusted accordingly.
We assume 225 equivalent days because a newly launched consumer marketplace commonly grows progressively as listings, buyers, and seller trust accumulate rather than operating at full scale from day one. If this is a brownfield launch with a full pre-existing dataset or a concentrated recent growth burst, this parameter can be adjusted accordingly.
Daily Marketplace Discovery
Weekday Seller Operations
Daily Marketplace Discovery
Daily Marketplace Discovery
30
times/month
1.08 req/s
Peak load
We assume a four-hour daily marketplace-discovery scenario because families commonly browse resale inventory after school and work without a single external signal forcing simultaneous access. Anonymous discovery and registered checkout are separated into different purposes because their intent, conversion, and write behavior differ. The scenario occurs every day, while the full period width is used because activity is expected to be spread across the window. If marketplace demand is concentrated into flash-sale moments, a narrower scenario can be introduced accordingly.
Main impact: Peak Concurrency
The scenarios above set the assumptions for each resource; below is the full calculation derived from them. Click to expand each item.
DEVELOPMENT SCOPE
How this app works
What exactly does this budget support? Broken down by business scenario, showing the pages, data tables, automation flows and AI assistant behind each one
Administrator reviews pending seller verification documents and records decisions.
Marketplace Page
users
Seller reviews paid orders and records shipment.
Marketplace Page
users
Seller checks verification state and submits a supporting document.
Marketplace Page
users
Seller views and updates account presentation, including a profile picture.
Marketplace Page
users
Seller reviews existing inventory and publishes a toy with pictures.
Marketplace Page
users
create_toy_listing
Buyer views and updates a display name or profile picture.
Marketplace Page
users
Buyer reviews a purchase, confirms delivery, and rates the seller.
Marketplace Page
users
create_toy_listing
Registered buyer discovers a toy and starts an escrow-backed purchase.
Marketplace Page
users
create_toy_listing
Public discovery of available pre-loved toys without registering.
Marketplace Page
users
page
data_table
action_flow
Verification Review Page
Administrative queue for reviewing seller verification evidence and recording decisions.
Seller Orders Page
Seller view of escrow-backed purchases and shipment controls.
Seller Verification Page
Seller verification request submission and status tracking.
Seller Listings Page
Seller inventory list and new toy publication form with multiple pictures.
Seller Profile Page
Seller account identity and picture management.
Purchases Page
Buyer order history, escrow status, delivery confirmation, and post-purchase rating controls.
Buyer Profile Page
Buyer account profile and picture management.
Toy Detail Page
Detailed toy information, pictures, seller trust information, ratings, and escrow purchase entry.
Marketplace Page
Public and registered-user catalogue of available pre-loved toys.
FAQ
What you might want to know about this project
The Q&A below is generated by AI based on this project's type, features and scale
Can buyers rate sellers before delivery?
How does escrow affect the backend design?
How is seller verification represented?
What will most affect this marketplace's resource usage?
Copy to discuss with AI
Challenge & re-estimate
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