I dont sell accounts with 1k-10k in bulk at a discount. I prefer to sell them individually to maximize profits. Occasionally I will offer a discounted price to get rid of excess accounts, however I cant seem to keep my accounts in stock since they sell to quickly, so bulk is not really an option at this time.
Great idea, I am actually doing something quite similar, but yet different. If you are selling an account, and the new owner is logging in from their residential IP, there should be little to no problems. Sure they might get a PV, however thats about it. I dont think you need to worry about this, You mainly want to worry about those who open a dispute or unauthorized transaction.