I am a sub/contractor for a pool company here. He has never said anything to me about kickbacks or % reduction. Generally I'll charge by the hour or load and that will depend on how many guys and what equipment I need. He pisses and moans but I do a good job,have the proper ewquipment for what is asked of me,and i show up when i'm supposed to.
I ran into a similar deal when i used to do foreclosed houses. when the lady toold me how much i would make and then told me I would be giving a 15% kickback for the work I told her,um hell no