Selling replicas on eBay seems tough. I'll be honest when I say that I registered on this site for new ideas... And my initial money making scheme, if you will, was to start selling replicas on eBay. After reading 90% of the posts here, it seems like a very bad idea.
However, I recommend, depending on where you live, to pick up some bootleg football jerseys. If you live in an area with small towns (a couple x000 ppl) get started by frequenting a few bars on game day and throw it in that you can get jerseys for 50$ a piece... You'll pay 23$ for them online and you'll make a pretty penny by playoffs.
The only hard part... ppl now know of these jersey wholesale sites... but if you find a crowd that don't... you'll be in. Where I live, if I stock up on two teams, I know that I will be in alot of money in a few months.