by UnderpricedApp | 2026-01-04 20:05:02+00:00
I’ve been thrifting and reselling electronics for about 5 years now.

I eventually got tired of the manual grind: checking every item via Google Lens or ChatGPT, checking eBay Sold listings, and manually adding data to my inventory spreadsheet. Every item took ~3 minutes to vet.

To solve this, several months ago I've launched Underpriced.app, a dedicated AI reseller app and AI thrift store price checker.

What Makes This Different from ChatGPT / Google Lens?
The main difference is that my flipping app combines AI visual analysis with actual eBay/marketplace price lookups to give you a realistic value estimate.

It works as a dedicated eBay price checker that answers "what is this worth" using real market data, not just hallucinations. It keeps every analysis in the same consistent format, making it much faster when you are scanning dozens of items. Plus, you can add any analyzed item to the built-in Flip Tracker with one click.

From the moment you spot an item to the point where it is analyzed and saved to your inventory, it takes 30–60 seconds. This makes it one of the best apps for resellers in 2025 regarding speed and accuracy.

What Each Analysis Gives You
A Deal Score (0–100) & Tier Rating: Immediate ratings (HOT / GOOD / FAIR / PASS) so you know instantly: "Is this worth buying?" and "Is this a good deal to flip?"

Net Profit & ROI: It’s not just about revenue; it’s about what you keep. The built-in reseller profit margin calculator factors in fees and shipping costs to show you exactly how much profit you can make and what you should realistically sell it for.

Sales Velocity & Platform Advice: The tool analyzes demand levels and recommends the best marketplace for the specific item—whether that's eBay, Poshmark, Facebook Marketplace, or Mercari. It functions as a listing analyzer and price checker for multiple platforms in one.

Identification & Confidence: Identifies the brand, model, year, and category with a confidence rating. This is perfect for identifying Goodwill finds worth money or acting as a vintage value checker.

Red Flags & Checklists: Warns you about potential fakes and provides category-specific inspection checklists (essential for learning how to know if something is worth flipping).

Speed: 15–45 seconds per analysis. You can upload 1–3 images depending on your plan (Free tier limited to 1 image).

Two Ways to Use It
1. Online Sourcing (Retail Arbitrage) Screenshot any listing from Facebook Marketplace, eBay, Craigslist, or OfferUp. Get an instant analysis of what it is, its value, your profit margin, and red flags.

2. In-Person Sourcing (Thrift/Garage Sales) At a thrift store or flea market? Snap a photo of the item and the price tag.

Built-In Inventory Tracker
I included a complete tracking system where you can log every item from sourcing to sale.

Track purchase price, source, listing location, final sale price, fees, and shipping.

Calculates total profit, average ROI, and average days to sell.

Shows which categories perform best for you.

Premium Tools (Reseller+ Plans)
Plan My Flip: Generates SEO-optimized titles, copy-paste ready descriptions, pricing strategies, photography tips, and platform recommendations.

eBay Comps: Pulls real sold listing data directly from eBay (median, low, and high prices)—actual sales, not asking prices.

Negotiator: Gives you leverage points, target prices, and copy-paste scripts to send sellers to negotiate better deals. (Still tweaking this to improve accuracy!)

Try It Free
The site is underpriced.app. You get 10 free analyses to start. No credit card required.

Feedback I'm Looking For
Does the analysis match your real-world experience?
Are the profit estimates realistic?
Is it fast enough for in-store sourcing?
How does it compare to other tools you’ve tried?

Any feedback, including negative, is helpful.

Happy thrifting!