Make sure you test everything on the phone even if you think it's not necessary, we're talking serious money here!
Always keep in mind that if a product is sold way below its original price, then there might be something wrong with it and since you're not getting it from a retailer, you can't ask your money back (this happened to me shortly after I had moved to the US, I needed a good smartphone and ended up with a crappy Samsung that didn't even have w-lan just because I hadn't checked!)