Ginny,

I've bought 4 bikes on ebay, all without much problems. I always ask the seller a question about the bike that requires them to measure something (top-tube c-c, or steerer tube length) anything that shows that there really is a bike. Check the category that it's listed under - a scammed account will show the bike in a weird category - there's a bike listed in the Blu-Ray DVD section - instant scam alert. And, anyone that asks you to email them before you bid is a scam.

Some of the frames had a little more wear than was indicated, so ask specific questions if they say there are scratches.