At the end of the day, it shouldnt really matter what the wholesaler makes. If the end buyer agrees it is a good deal, then profit doesnt come into play. Many wholesales have formulas they use and their purchase price builds in the profit they want to make on the deal. If they can negotiate it at that price then it works for everyone. If a good deal is buying property X at 40k, but the wholesaler is able to negotiate and buy it for 15k, why shouldn't he take a sizable profit? I know wholesalers who consistently make 8k on deals and have a customer base that keeps coming back for more because they are truly good deals in the end.
What I dont agree with is a wholesaler not being able to negotiate the price that is right for him/herself and the end buyer, yet trying to still take their sizable profit. Good wholesalers are good negotiators and unfortunately they can use this tactic with inexperienced buyers. While buyers should have a good understanding of the market and deals themselves going into it, alot of beginners rely on mentors and wholesalers to help them get started.