Pricing per professional mix for each song?

Im an upcoming artist whose art if at industry level and i’m searching for a steady engineer to work with to to give my tracks that industry quality sound. I was wondering what your pricing was, and what your turn around time looked like. Im a college student and im paying rent on my own but i dont kind investing in my future

Additional info:
. I need the vocals tuned as well. I'm looking to hire a top pro who's worked on hit songs, and have the budget for that. The song has less than 10 tracks recorded that need mixing. I'll need you to master it too if possible. I don't have a hard deadline for this.