For budgeting purposes, you can generally plan on 4 to 6 hours to mix a song. If you're interested in my mixing services for the next "Bohemian Rhapsody", well...that could take a few more hours. Conversely, if it's a vocal and an acoustic guitar, it will likely take less than 4 hours.
Upon completion of your mixes, I will send them to you for your approval. Your feedback is essential! I understand you may want to make a few revisions. I do that with my own recordings. I encourage you to make a detailed list of what you would like to hear differently (i.e. a bit more delay on a vocal, the two guitars spaced a bit wider, etc.), and combine them into one revision. I offer up to 3 revisions at no charge.