I offer in-the-box mixing in workstations like Protools and Logic Pro. Mixing is the art of merging every element of the song to make it sound like you want it, so that it has all the power and character to express what you wanted to.
For 5$ I will:
Do balancing of the tracks (volume adjustments)
Correct phasing problems
Basic eq'ing and compression
For 10$ more I will add:
Effects (Delays, Reverbs, etc) to whatever instrument or vocal that needs it
For 15$ more I will add other mixing techniques:
Automations (for panning, volumes, etc)
In-depth eq'ing and compression (side-chain compression)
Use of distortion (not like a guitar type of thing; it is surely a nice touch)
Every price is for 1 song of up to 4 minutes, and the song may not exceed 15 tracks. For 15 tracks extra I charge 5$ more.