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:
The song has less than 10 tracks recorded that need mixing. I don't have a hard deadline for this. . 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. I'll need you to master it too if possible.