If you factor in all the costs with buying and shipping a wedding dress, you should have a good idea of the actual price. Now if it sounds too good to be true, it probably is.
As long as there are buyers willing to buy from China, there will always be sellers there, happy to take your money. Bridal boutiques here that sell beautiful gowns hand made in the orient, have agents there, that deal directly with the makers. Those dresses are probably not sold on ebay.
I'd have thought, Once bitten, twice shy.