Appreciate all of the responses and thoughts! I'm glad to know I'm not clear out in left field in at least thinking about a wooden floor. As far as cost goes, my math went something like this:
If I used I-Joists (something like this: http://www.menards.com/main/building...056-c-5662.htm
), I'd need approximately 23 of them to cover that 20x30 area at 16" OC.
23 x $30.80 = $708.40
If I covered that with 3/4" subfloor (something like this: http://www.menards.com/main/osb/3-42...33-c-13333.htm
), I'd need approximately 20 sheets to cover the entire floor.
20 x $13.58 = $271.60
Add in a couple of hundred bucks worth of hardware and whatever, and I end up with a total bill for a wood floor of:
$708.40 + $271.60 + $200 = $1,180
During my talks with builders and concrete guys, I've had estimates anywhere from $7,500 - $10,250 to pour a 4" slab in the entire building + a 20'x20' approach up to the garage door, which results in a total of 1600 sq ft, at 4" thick. If I use the $7500 and divide by 1600sf, I end up with $4.69/sf of finished, 4" concrete. I'm not entirely sure how concrete costs are calculated, but if I take that $4.69/sf and apply it to my 20x30 shop space, I end up with:
$4.69/sf * 600sf = $2,814
So, at the end of the day, a wood floor in the shop ends up being somewhere around $1,700 cheaper, depending on which concrete estimate I use. Does that sound reasonable-ish? It seems I could even put down two layers of subfloor and still be quite a bit of money ahead.