Wow $4/day thats cheap at twice the price. that clinches it I'm going AC for sure now

I'm about 40 miles North of San Antonio. My shop is a 40x40 General Steel Building.
When I put the shop up I put insulation on the ceiling and the walls. I put in the biggest
Mr Slim heat pump in. She stay about 80 in the Summer and 70 in the Winter. It is economic
to run.

If you have heat in your garage, I would guess it's insulated. All you would need to cool/dehumidify an insulated two-car garage is a 6000 Btu window unit if you were willing to turn it on early in the evening and let it run all night... say on a Friday night if you were gonna be out there on Saturday.

I once cooled almost our whole downstairs for about a week with a "friend loaner" 5500-6000 Btu Haier in a back bedroom and a coupla floor fans in August/September while we had a new HVAC system and ducting installed. The dehumidification those things can perform is amazing. I turned in on (full blast on high) about 7 or 8 PM after I got it in the window, and by morning, it was 74 and comfortable.

Go bigger and you could wait to turn it on when you go to bed or first thing in the morning.