Okay, got me some estimates on drywall. Ceiling and one wall has old drywall that has to come out. Material, labor, and demolition is 1500$ Trash dump is 100$.. This is a 20x24 garage will 10ft ceiling.. Is that a good price for drywall? He will paint and hang lights for 500 more clams..
Sounds high......
Why not do the work yourself....it's not hard.....that is what beer and friends are for.
BTW....my garage is 'almost' the same size....see the link in my sig for pics.
In any case....before you get the walls done...DO THE ELECTRICAL. Much easier to run romex when your not dealing with drywall.
Some common things you will see here on GJ....it's never big enough....you never have enough outlets....or light....
So go grab a beer (or two), sit down and start searching...keywords, drywall, OSB, outlets, air lines, lighting, cabinets, concrete sealing, and tunes.