When I did my shop in Upstate NY, it was 28x34 and I had 4' formed foundation walls/footings, with a 4" 4000PSI Concrete floor it cost me around $12k for it all.
This was a little over a year ago.
Re: Screw in light reflector
I put 8 of them in my garage with 105W CFLs in them. Makes a HUGE difference in the amt of light hitting the floor instead of being wasted on the ceiling.