Every reseller knows the feeling: you spot a Game Boy Micro for €100 on Vinted, you're pretty sure it flips for more on eBay, but by the time you've checked sold listings, filtered out the broken ones and done the fee math, someone else bought it.
The problem isn't finding listings — it's valuing them fast. So I automated the whole loop: scan live listings on Vinted, Wallapop and Milanuncios, value each item against confirmed eBay sold prices (not asking prices!), subtract every fee, and return only the listings with real profit in them. This tutorial shows you how to run it yourself in 5 minutes, across Spain, France, Germany, Italy or the UK.
Why most "deal finding" fails
Three traps kill naive flipping bots:
Asking prices lie. eBay is full of Game Boy Micros listed at €400 that never sell. The only truth is Sold listings — what buyers actually paid. Any valuation built on active listings is fantasy.
