A starter guide

People guess prices.
Your phone can check them.

Buy used stuff that's priced way too low. Resell it for what it really sells for. No business experience needed.

Oct 10, 2026 · Billy Howell on X

He took one photo of a card shop's display case. His AI bot priced all 40 Pokémon cards against recent sales in about two minutes, for about a penny.

Deal

A Hitmonchan card priced 30% below what it usually sells for.

Trap

A "$300 Charizard" that was really a reprint worth about $160.

1

Sellers guess

Nobody running a garage sale looks up 100 items.

2

AI knows what things are

Spotting a valuable item used to take years. Now a photo gets you a good first guess.

3

It won't last

Shops will catch on first. One-time sellers, like a family clearing out a house, will take longer.

Priced $4→Sold for $60 Example numbers
Step 1 · Snap

Where to look

Go where the seller is an amateur, in a hurry or pricing lots of things at once. Pick one or two.

Start here

Estate sales

Most post photos a few days early on EstateSales.net. Check them at home, then arrive early for what you flagged.

Tip: many cut prices on the last day.

Facebook Marketplace

Vague titles like "old chair" or "box of Legos." Nobody searching the real name finds them.

Tip: check "Free" and moving sales.

Thrift stores

Video games, records, Lego, brand-name tools.

Tip: skip books. Scanner apps picked them over years ago.

Online auctions

"Mixed lot" photos on ShopGoodwill or HiBid. Have the AI list every item, then add them up.

Tip: set your top bid first.

Card and collectible shops

Shops that price with stickers. This is what Billy did.

Tip: ask before photographing the case.

Pawn shops

Guitars, amps and tools. They price a bit of everything.

Tip: sticker prices are usually negotiable.

Step 2 · Check

Ask the AI, then check eBay

The AI tells you what it is. eBay's sold listings tell you what it's worth.

① Paste this with your photo

I'm thinking about buying the item(s) in this photo to resell. For each item:
1. What exactly is it? Brand, model, set, year or edition.
2. How sure are you? High, medium or low.
3. What changes the value (condition, edition, missing parts, signs of a fake or reprint), and what should I check in person?
4. What exact words should I search on eBay to find SOLD listings?
5. Roughly what does it sell for used? Say if you're unsure.
Asking price: $___

Works in ChatGPT, Claude or Gemini.

② Check real sale prices

  1. In the eBay app, search the words the AI gave you.
  2. Tap Filter and turn on Sold items.
  3. Look at about 10 recent sales of the same item in the same condition.
  4. Take a price from the middle. Ignore the highest one.
  5. If only one or two sold in three months, yours may sit a long time.
The AI's price is only a hint. If something looks wildly cheap, it's often a misread or a fake. Billy's own setup flags those to double-check.
Before you pay

Do the math

Fees and shipping eat into every sale. Type in your numbers.

$
Middle of recent sold prices
$
What you'd pay
%
eBay about 13 to 15%. Facebook pickup 0%
$
$0 if the buyer picks it up
You keep$0
Profit$0
Return0%

Rule of thumb:buy when profit is at least what you paid, and at least $15. Your time and gas count too.
Step 3 · Flip

Sell it

List each thing where its buyers already shop.

Small things you can shipeBay
Furniture and big itemsFacebook, local pickup
Trading cardseBay or TCGplayer
Vinyl recordsDiscogs
Guitars and music gearReverb
LegoBrickLink or eBay
  • Shoot photos in daylight, and show any damage.
  • Copy the title style of listings that already sold.
  • Price near the middle of recent sales. Drop it a bit after two weeks.
  • Ship within a day or two. Early good reviews help every later sale.
Your first month

Start small

Month one is practice. Keep the budget small enough that mistakes don't hurt. $100 to $200 is plenty.

Week 1

Learn one category. Browse eBay sold listings until you can guess prices before you look.

Week 2

Buy 3 to 5 things that pass the math. No more.

Week 3

List everything. Note the day each one sells.

Week 4

Review. Do more of what sold. Stop buying what sat.

Download the tracker spreadsheet

Don't

  • Trust the AI's price without checking sold listings.
  • Compare against asking prices. Only sold prices count.
  • Buy things that rarely sell, even cheap ones.
  • Fill a closet before you've sold what you have.
  • Forget to log every sale. Profit is taxable, and eBay can report your sales to the IRS.