IPhone 4 off eBay?????

They're alot cheaper off eBay and I don't care it doesn't have to be new just in good shape and they're sold cheaply there, but is eBay like secure? Will I get a good condition iPhone? I've never bought off there, and I don't want to get tricked or something? I don't know is it a good idea to buy a 32g iphone4 off there?