I have ordered items on eBay just for the seller to order it on Amazon and send it to me that way. Just happened to me this week with club bells/Indian clubs.

Haha, I ordered my car wing mirror cowl and it arrived in a box with an Amazon gift receipt. I suppose the eBay fellow was solving a discovery problem for me for a cut. Good for him.

IIRC that's against eBay's rules. But people still do it when the spread is enough to make it worth the risk.