Last week someone called my LEGO investment toolkit "AI slop." Fair. Here's how it actually works.
Posted bricktracker.net here last week. Got 2.3K views, a handful of useful comments, and one person who said "more AI slop." Fair enough — most "LEGO investing tools" are scraper sites with no real curation. Let me show what's actually under the hood, address the resale bug a few of you hit, and explain the parts people asked about.
On the "AI slop" critique:
Honest answer — the SITE looks polished because I care about UX. The DATA isn't AI. Here's where it actually comes from:
- Set metadata (names, piece counts, themes, images): pulled live from the Rebrickable API
- Retail prices: manually curated daily — I check Amazon, Walmart, Target, Best Buy, and LEGO.com myself and update the database
- Resale prices: BrickEconomy averages, validated against eBay sold listings for the top retiring sets
- Retirement dates: cross-referenced between Brickset, Brickfanatics, and LEGO's own announcements
- Deal of the Day: I pick it manually each morning based on a scoring rubric (discount %, retirement proximity, historical appreciation, resale velocity). No AI is making the call.
Tool stack is Supabase + Netlify functions + vanilla HTML/JS. No ML, no scraping bots, no auto-generated content.
The slop critique probably came from how clean the layout is. Trade-off I made on purpose — I'd rather it look like a real product than a hobbyist spreadsheet. But I get why "polished + LEGO investing tool + free + new" pattern-matches to AI dropshipping sites. Hopefully this clears it up.
Bug a few of you flagged last week:
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You were right. Some of the resale prices weren't loading when sets got added to My Collection — issue was on the lookup function side, not the data itself. Fixed this week. If you saw it last time, refresh the page and add the set again. Should populate correctly now.
If it doesn't, drop a comment with the set number and I'll dig in directly.
On "how does it work" — quick walkthrough:
A few of you asked how to actually use the site. Four pages worth checking:
- Homepage: search any set, see live retail + resale + map of nearby retailers with stock indicators (Best Buy is live, Target + Walmart in progress)
- Hot Deals: filtered list of every tracked set sorted by flip margin %. Featured "Deal of the Day" pin at the top.
- Retiring Soon: countdown timer to retirement for every set with a confirmed EOL date. This is the page most of you said you wanted.
- My Collection: add the sets you own, see real-time portfolio value, ROI per set, and total margin. Sign-in optional — works in browser local storage if you don't want an account.
Watchlists support price alerts (free, email-based). Daily cron checks every alert and emails when targets cross.
What I've added since last week's post:
- Fixed the resale-on-collection bug above
- Added a daily "Deal of the Day" feature that auto-pins the strongest current deal to the Hot Deals page
- Reworked the Hot Deals sort logic — now defaults to flip margin percentage instead of dollar amount (better signal for ROI plays vs. just expensive sets with thin margins)
- Added the Brick Trader marketplace stub page (coming this summer — P2P sales between users)
Still on the list (haven't built yet):
- BrickLink price sync (manual is fine for now but doesn't scale to 1000+ sets)
- Walmart + Target real-time stock APIs (Best Buy is live, the other two are next)
- Minifig-only search and tracking
- Pro tier with email alerts at custom thresholds (free version works, Pro is for power users)
Honest priorities — building solo, paying for the APIs and hosting out of pocket, so things ship at the pace I can actually maintain.
Discussion
A few things I'd genuinely like to hear back on:
- For the bug fixers: did the collection page work for you this week, or still issues?
- For the "haven't dug in yet" folks: anything specific that would make you actually use it daily? Email digest? Better mobile layout? Different sort options?
- For the "AI slop" person (if you're still reading): what would change your mind? Always open to specific feedback.
Free, no signup required for the deal feed, no affiliate links pushed in your face. Comment with set numbers you want priced, I'll add them.