12 songs mixed (and mastered?)

Hey there! I have 12 album tracks that I have already arranged and mixed myself, however I think it could really use the polish from a pro like yourself. I was wondering: * What the cost would be per song / the whole album * If the files produced will need subsequent mastering separately? Many thanks! Sebastian

Additional info:
I'm an indie artist. The song has somewhere between 10 and 30 tracks recorded that need mixing. I'm interested in working with a very experienced mixer. The tracks are cleaned, tuned, and and the song is ready to be mixed. I'll need you to master it too if possible.