I've been looking on ebay for a dress too, to see if there was anything I liked. The individual sellers don't worry me and the bridal shops in the states don't worry me, but the ones in China that say they make the dresses, scare me. I don't know why, it just makes me really nervous.
I've never had any problems with any of the other transactions I've done on ebay.
Oh, one thing, I sold a few things on ebay and usually I only ship within the U.S. but one person from canada asked for something and another from mexico. So I said yes, shipped the items, the one going to canada was supposed to take up to 2 weeks, it was 2 months before he received it, and the one to mexico was supposed to be 2-3 weeks, it was 3-4 months before he received his stuff. I felt so bad for both of these people, they did get them, but it took a lot longer than expected. This was through the USPS, so just be sure to use fedex or ups or some type of guaranteed service just to be sure.