pierre, actually from a western point of view $400 for an anal scene in russia is very less. but for bg classic they even only get $200 what is a a rip off, no doubt!
anyway of course you dont overpay the girls for charity. you take a lot from them in exchange often including exclusivity. also i dont know what you pay them in russia, but for sure not the same like in europe.
lets call the peanuts simply "market price".
every european model must ask herself if it is better to do one exclusive (either contract or other promises) scene for one producer for 3 times the market price OR to do 3 and up scenes for market price and different producers. pretty sure most consumers (excluding your fans) will prefer the 2nd option. about the models it is different as you know you can never predict a woman's action.
thats my opinion, it is up to you if you feel accused.