Use the Salehoo directory for your authentic shoes. I have found a couple sites within the directory that sell authentic shoes at reasonable prices...however if you are not buying the shoes for yourself, or you aren't going to resell them at retail value, you will find you probably won't make much profit from them trying to resell them.
Check out eBay and you will understand what I am talking about. The Nikes and Bapes that sell for around $60 are fakes but the sellers make more from them then those who sell the real shoes for $100-$300. The fake ones sell for less but attract more buyers whereas the authentics get more money from each shoe but less buyers are willing to pay the money.