This presents an interesting dilemma - if you're shipping a physical USB drive - the drive + shipping is going to run you a minimum of ~$15 - that means IMO you'd probably want to sell at least 1.5-2 LTC per transaction, but losing a potential dispute would hurt much more, and eBay/Paypal are notoriously wishywashy about these types of things. I doubt when it comes down to it, citing "eBay rep 3: John" is really going to help.

When I started selling BTC/LTC on eBay a few months ago when BTC was ~$150 and LTC was ~$3 - I only dealt in small chunks - 0.01-0.05BTC and 1LTC because there were so many frequent scammers that if I lost one or two disputes here and there it didn't really affect me.

This does cover the case of the spammer though - most of these guys steal eBay/Paypal accounts and just charge with the credit cards, because they know once you send over the BTC/LTC, the actual person is going to see the weird transaction, dispute it, then win. Now, if you're sending to the actual address it's much harder to dispute.