eBay is the largest pool of card buyers outside the shop door. It is also the least forgiving channel to run badly.
The case for
- Reach far beyond your local area, which matters most for cards with a thin local market.
- Buyers who already trust the platform, so you are not asking a stranger to trust you first.
- Price discovery. You find out quickly what your stock is actually worth.
The costs, honestly
- Fees, which come off every sale before you count margin.
- Returns, which land more often than in-store and are largely at the seller's discretion in name only.
- Defects. Cancelling because you sold the card in-store damages your seller standing.
- Time. Photographing, listing, packing and posting is real work per card.
When it is not worth it
For low-value singles, the fee plus postage plus the ten minutes of work exceeds the margin. eBay pays for cards above roughly the point where postage stops dominating — where exactly depends on your fees and your time.
Running it without doubling your workload
The workload problem and the overselling problem are the same problem: eBay as a second, separate inventory. Draw the listings from the same stock as the shop and the show table and both go away.
Here, eBay stock is allocated from the same intake, listings are drafted and published to your own eBay account, a live listing can be revised in place rather than ended and relisted, and a sale on any channel decrements everything else. See the eBay guide.