I do this for a living. You are correct. The way I work is a fixed fee in advanced based on rough estimates of the final value of the domain. Consequently I get

I do this for a living. You are correct. The way I work is a fixed fee in advanced based on rough estimates of the final value of the domain. Consequently I get paid the same but I'm incentivized to purchase as cheaply as possible in order to get referral business (but not at the expense of making money).