So I built Underpriced.app - an AI reseller app that tells you if something is worth flipping before you buy it.
The Problem
Researching items takes ~5 minutes per item You waste time and miss deals while researching (someone else grabs it) You buy blindly and hope for the best Spreadsheet tracking is tedious
The Solution
Take a photo or screenshot → AI identifies the item → Get instant analysis: Profit potential after all fees ROI percentage Demand level & time to sell Best platforms to sell on Red flags to watch for Deal score (0-100)
Tech Stack
Frontend: Next.js, React, TailwindCSS Backend: Node.js, PostgreSQL Chrome Extension for browser integration
Features I'm Proud Of
Works for both online sourcing (screenshots) and in-person (photos) Built-in flip tracker with analytics & reports Chrome extension for one-click online deals analysis Premium AI tools: flipping strategy, listing generators, deep market research 15-30 second analysis time
Current Status
Launched 2 months ago 10 free analyses to start Paid tiers from $2.99/mo Active users in flipping community
What I'm Working On More accurate valuations for niche items Multi-item batch analysis Mobile app (currently PWA) Integration with inventory management tools
Lessons Learned AI vision models are incredible but need heavy prompt engineering Promoting SaaS is way harder than building it The reselling community is way bigger than I expected Balance between speed and accuracy is crucial
Try it: underpriced.app
Would love feedback from fellow builders:
How would you improve the AI prompts for better accuracy? What's a fair price for this kind of analysis tool? Should I focus on depth (better analysis) or breadth (more features)? Happy to answer any technical questions about the build!