a marketplace app for 500 buyers
PROJECT OVERVIEW
What this app does
This project is a multi-seller marketplace app designed to support approximately 500 registered buyers and a smaller seller community. Buyers can browse listings, view listing details, complete payment, and review orders, while sellers can publish listings with images, maintain availability, and fulfill purchased items.
As an anonymous visitor, I can browse available listings and view listing details
As a buyer, I can browse available listings and evaluate listing details
As a buyer, I can place an order and complete payment for selected listings
As a buyer, I can review my order, payment, and fulfillment history
As a seller, I can create listings and upload listing images
As a seller, I can review and update my listings and availability
As a seller, I can view purchased line items and update their fulfillment status
The following user counts are projected totals after one year of growth
500
buyers
Registered marketplace customers who browse listings, complete payment, and review their orders.
25
sellers
Registered marketplace suppliers who create listings, upload images, maintain availability, and fulfill purchased items.
1000
anonymous_visitors
Public visitors who can browse available listings and view listing details without a registered account.
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
The marketplace requires buyer payment collection, so at least the PRO plan is required.
See the capability-by-capability assessment ▾
PROJECT DEMAND
ALLOWANCE PROVIDED (COMPOSITION)
PRO
x 1
Pro is the minimum viable plan
Pro
(Plan tier: PRO)
See minimum viable plan above
$ 99
single-tenant kit
x 0
1 req/s
not purchased
(plan/kit 25 req/s)
Covered by plan/kit (margin ~2400%)
$ 0
Database storage add-on
x 0
34.18 MB
not purchased
(plan/kit 1.00 GB)
Covered by plan/kit (margin ~2826%)
$ 0
Object storage
add-on
x 0
1.41 GB
not purchased
(plan/kit 10.00 GB)
Covered by plan/kit (margin ~610%)
$ 0
Outbound data transfer add-on
x 2
52.68 GB/mo
500GB × 2/year, amortized monthly
(plan/kit 10.00 GB/mo + add-on +42.68 GB/mo)
Add-on fills +42.68 GB/mo gap beyond plan/kit
$ 5.83
AI points add-on
x 0
0 points
not purchased
(plan/kit 5.0M points)
No requirement
$ 0
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 $104.83/mo all-in above.
Current usage sizing
AWS list pricing
2 × t4g.large × 730h
EC2 t4g.large → 98.11
2 × db.m6g.large (Multi-AZ) × 730h
RDS PostgreSQL db.m6g.large → 232.14
0.03 GB-month
RDS gp3 storage → 0
1.41 GB-month
S3 Standard → 0.03
0.00 GB (first 100GB free)
Internet egress → 0
Total ≈ $330.29 / mo
Pure cloud resources
DEVELOPMENT COST
MONTHLY CLOUD INFRA ($/MO)
MONTHLY TOTAL (INFRA + OPS, EXCL. AI USAGE)
Traditional outsourcing / build in-house
about $85,000 - $125,000
≈ $330
Based on the AWS estimate above
≈ $2,330
Infra $330 + ops ~$2,000
4-6 months
5 / 5
Vibe Coding
about $16,000 - $23,000
≈ $330
Based on the AWS estimate above
≈ $1,830
Infra $330 + ops ~$1,500
hours
5 / 5
AI full-stack generation
about $7,000 - $10,000
≈ $330
Based on the AWS estimate above
≈ $1,830
Infra $330 + 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
$105
All-in: egress / storage / auto-scaling; excludes AI usage
$105
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 ≈ $330.29/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 approximately 500 registered buyers because that figure is explicitly stated, with a much smaller pool of about 25 registered sellers because a marketplace needs supply-side accounts and a modest seller-to-buyer ratio is typical at this scale. Anonymous visitors are excluded from this registered total and modeled separately. If your actual business operations differ, such as having an open seller onboarding campaign or internal operator accounts, this parameter can be adjusted accordingly.
We assume 225 equivalent accumulation days because a newly launched marketplace normally follows standard linear growth as buyers, sellers, listings, and orders build over the first year. There is no indication of a launch with a full pre-existing dataset or a sudden recent traffic burst. If your actual business operations differ, such as importing a mature catalog and order history at launch, this parameter can be adjusted accordingly.
Daily Order Status Review
Daily Order Status Review
Daily Public Discovery
Daily Public Discovery
30
times/month
0.05 req/s
Peak load
We assume buyer order review occupies a two-hour daily scenario because customers commonly check payment or fulfillment progress in short account-focused visits distributed across an evening period. It is modeled separately from checkout to avoid treating every order-history reader as a new purchaser. Daily recurrence reflects ongoing order monitoring. If your actual business operations differ, such as status checks being driven by delivery notifications at specific times, the duration and frequency can be adjusted 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
Public discovery journey for visitors who browse listings without signing in.
Marketplace Browse Page
users
Registered buyer journey from marketplace discovery through hosted payment checkout.
Marketplace Browse Page
users
start_marketplace_checkout
Registered buyer review of payment and fulfillment history.
Marketplace Browse Page
users
Seller workflow for creating and maintaining a listing and its image gallery.
Marketplace Browse Page
users
Seller workflow for reviewing purchased line items and updating their fulfillment progress.
Marketplace Browse Page
users
page
data_table
action_flow
Marketplace Browse Page
Public marketplace discovery page for browsing and searching available listings.
Listing Detail Page
Detailed presentation of one listing, including its description, price, seller, and images.
Buyer Checkout Page
Review and payment page where a registered buyer confirms selected listings and starts checkout.
Buyer Orders Page
Account page showing a buyer's marketplace order, payment, and fulfillment history.
Seller Listings Page
Seller workspace for creating, viewing, and updating marketplace listings and their images.
Seller Orders Page
Seller workspace for reviewing and fulfilling purchased line items.
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
What will drive resource usage for this marketplace?
Which marketplace features are included?
Is the design sized specifically for approximately 500 buyers?
How do listing images affect capacity?
Copy to discuss with AI
Challenge & re-estimate
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