With jerseys, the first decision is which version you actually want, because "fan" and "player/authentic" versions differ in fabric, cut, and how badges and names are applied. Oopbuy adds no service fee, so put that saving toward getting the version and lettering right rather than paying for the wrong one twice.
Understand the two common builds before you browse finds on W2CSpreadsheet:
Sizing is where jerseys catch people out. Player versions are cut close to the body, so many buyers size up one from their normal tee size; fan versions are roomier. Don't trust the letter alone, measure a shirt that fits and compare pit-to-pit and length to the listing chart. Football, basketball, and baseball cuts also differ, so read the chart specific to that jersey.
The detail work is what separates a good jersey from an obvious one, so use your QC photos to confirm:
If you want a specific player, season, and patch combination, state it clearly and verify it in the QC stage, since a name-and-number set is applied per order and mistakes happen. Getting confirmation before shipping is far easier than fixing it after.
Jerseys are light and fold flat, making them easy to consolidate into a shared Oopbuy parcel without much added freight. For live shipping estimates, pricing, and any active promotions, check the current Oopbuy listing rather than older figures. Decide fan vs player, get the size run right for that cut, and confirm the lettering in photos, and you'll avoid the three mistakes that account for most jersey returns.