@zlone Yes it’s a fair price. And you can install it yourself, as you have done before. Circuit breaker is still a 20 amp...
With Romex, after you get out of the panel try to keep it, (with in reason), at least 12" from other Romex cables all the way to the new wall outlet. Helps to prevent induced voltage and noise from other current carrying Romex cables onto the dedicated branch circuit wiring for your audio equipment.
Aluminum MC Cable, imo, for feeding audio equipment is better than Romex, but, it’s not for a layman to install. Care must be taken when cutting and removing the metal cladding from the wires for make-up on both ends. For 10-2 solid copper for a clean cut job a hacksaw works well. For 12-2 MC cable I have a tool that cuts the aluminum clad. Also, though NEC does not require anti short bushings, They are a must, imo...I don’t care how great an electrician thinks he is.