I Built a Self-Hosted Competitor Price Monitor Because SaaS Pricing Is Out of Control

The Problem

I run a small online store. To stay competitive, I needed to track my competitors' pricing. The obvious solution? Sign up for a SaaS price monitoring tool.

Then I saw the prices:

• Prisync: $99/month
• Price2Spy: $20-58/month
• Keepa: $29/month (Amazon only)

For a small operation, $99/month is absurd. So I built my own.

What I Built: MarketEye

MarketEye is a self-hosted competitor price monitor. You run it on your own machine, point it at any product URL, and it tracks price changes automatically.

Tech stack: Python + FastAPI + SQLite + APScheduler

Features:

• Drop any product URL → auto price tracking
• Email + webhook alerts on price changes
• Price history charts + CSV/JSON export
• Works with Amazon, Shopify, JD, Taobao, any HTML page
• Web dashboard included (no CLI needed)

How It Works

1. Add a product URL through the web dashboard
2. MarketEye scrapes the page at configurable intervals
3. When a price changes, you get an alert
4. All data stays on your machine - no cloud, no third party

The scraping engine handles various e-commerce platforms out of the box and provides a plugin interface for custom scrapers.

Why Self-Hosted?

• One-time payment: $49 vs $99/month ($3,564 over 3 years)
• Unlimited products: no per-product fees
• Data privacy: your pricing data never leaves your machine
• Customizable: full Python source, extend it however you want

What's Next

I'll be sharing more technical deep-dives on the architecture, scraping challenges, and lessons learned from building and shipping this as a solo developer.

Check it out: MarketEye on Gumroad

Questions and feedback welcome! 🚀