"I built an AI app because my wife spent hours pricing thrift finds
My wife resells on eBay. She's good at finding underpriced items at thrift stores, but spent hours researching what to charge for each one.
Every item meant opening eBay, searching sold listings, comparing conditions, checking multiple results. For a $30 item. Repeat 20x per week.
I'm a developer, so I built her a tool:
📸 Snap a photo
🤖 AI identifies item + shows value with real sold comps
🛒 One-click list to eBay
What took 15-20 minutes now takes 15 seconds.
She's been using it for months. Decided to open it up for other resellers. Called it Underpriced AI® → underpricedai.com
Side note: Already have a troll claiming I stole "his" name and idea. The name is trademarked (his isn't). And AI pricing tools aren't exactly new - there are plenty out there. We just focused on doing it better.
Welcome to building in public I guess.
Check it out → underpricedai.com
Anyone else here in the reselling/flipping space?
Really interesting concept, resellers constantly make buying decisions with incomplete information so having real sold data in seconds is genuinely useful.
One thing I noticed on the landing page: the hero doesn't show the scan result visually. For a product where the magic is literally a photo turning into pricing data in seconds, showing that immediately would be more convincing than any description. The "wow" moment is in the output, put it front and centre.
Also the trust signals (96% accuracy, 6 platforms) are buried in paragraphs where most visitors miss them. Those numbers are strong — they deserve to stand out visually.
Happy to share a few more things I noticed if useful.
Good idea, good promotion.
Beautiful example on how to find a problem that matter for you.
The only question - how to find a tip to put your link somewhere in output like free mail service put powered by link inside every mail sent? It gives you a chance to grow using customers.
Nice product, congrats on the launch. Curious what channels you’re currently using to get users?
Thanks! Channels so far:
1. Reddit - r/flipping, r/ebay, r/thriftstorehauls. Resellers hang out there and are very engaged. Comment genuinely, don't spam.
2. SEO (long game) - Just launched a blog targeting "how to price thrift store finds" type queries. Too early to see results but planting seeds.
3. This community - IH and HN have been great for early feedback and a few signups.
4. Word of mouth - Built a referral program (give 3 scans, get 3 scans). Resellers talk to each other at estate sales and flea markets.
Biggest learning: timing matters. Resellers are weekend warriors - engagement spikes Fri-Sun. So I time emails and posts for Friday afternoon.
What's worked for you?
This is a solid analysis, especially the insights on timing. The Friday to Sunday engagement window is something many people overlook, so it’s smart that you’re focusing on it.
In similar reseller markets, I’ve seen success with pairing those high-engagement weekends with discussion-style Reddit posts or comment threads. These can highlight real pricing or sourcing workflows and help reinforce word-of-mouth without feeling overly promotional. Out of curiosity, are you planning to further invest in this approach?
Appreciate that - and yes, absolutely. Reddit is actually where I see the most natural fit for this approach.
Subs like r/Flipping, r/ThriftStoreHauls, and r/whatsthisworth already have people asking "what's this worth?" and sharing their finds daily. Contributing genuine answers there (with or without mentioning my tool) builds credibility in a way that no ad or promo post can.
The plan is to lean more into this - sharing real sourcing workflows, pricing breakdowns on specific items, and lessons from actual flips. The kind of content that's useful on its own. If people check out the tool from my profile or a natural mention, great. If not, I've still helped someone and stayed visible in the community.
The weekend timing pairs perfectly with this because that's when resellers are actively out sourcing at estate sales and thrift stores.
They're posting finds, asking questions, and most engaged with the community. Showing up with helpful answers during those peak moments is way more effective than a scheduled promo post on a Tuesday.
Still early in testing what resonates, but the discussion-first approach has felt right so far. Engagement is more genuine and the conversations often surface product ideas I wouldn't have thought of on my own.
This is a very insightful breakdown, particularly the distinction between being helpful with or without mentioning the tool. That mindset is exactly why this approach is effective in reseller communities.
One thing I’ve noticed as this approach gains traction is that the real leverage comes from intent clustering. This means identifying the 2–3 recurring questions, such as “What’s this worth?”, “Is this worth picking up?”, and “How would you price this?” You can then intentionally engage in those discussions during your peak window from Friday to Sunday.
When this is done consistently, it creates a pattern where people begin to recognize you as the pricing expert in the community. This recognition leads to more profile clicks and organic discovery of your tool, without needing any promotions.
If you’re interested in turning this into a more repeatable system, like determining which threads to prioritize, how frequently to engage, and how to test different approaches to drive more profile visits, I’d be happy to share how I typically structure this for Reddit-first products.