Ok so started the bid process on a few items.
Going with spray foam. I called 2 guys. One was a referral, he was $2000 for 1" of closed cell foam for the entire hut. He feels that 1" will give me R7, but that the extra air tightness will make the unit easier to heat. Plus he will tuck all my corners and edges around the end walls and spray all the floor troughs to make them water tight before I put down cement. The other guy insisted I needed 2" and it was $3800. But he wasn't going to do the extras either. My neighbor referred the 1st guy and has done 2 large barns over 5000 sq ft. I am going with guy number 1. This winter will be the only way to test it. He said if I needed more, he would come back and do for less than $2000 but he thinks I will be fine.
Next, had the dirt working guy come out. He thinks it will be $500 to excavate and level the floor. We expect that with the topsoil coming out, and needed to get to clay, I will put a foot of base inside. The base will be ground concrete instead of sand. Few reasons, but it will pack tighter and drain better than sand. Cost is the same. He's done hundreds of floors and this is how he prefers to do them. He did this way in his 3000 sq ft shop and drives his dump trucks in all the time. Concrete Dirt was $375 for 28 yards
Next was the concrete. My buddies are awesome and work for $20 hr/ and there are 3 of them. They can pour the cement in one day and will come back and saw cut. Total pour labor costs $700-750 which works out to be less than $1/sqft. Going rate here is $1.50/sqft for the labor. Concrete is 14 yards at $105 plus fiber fill so $120/yrd is $1800 with tax.
Setting up the floor for radiant heat, mainly pex and foam right now. I decided to buy the panels with the pex prerouted. The pex should only be about $500 for the garage. So I just need to price the panels.
Finally, Electrical. I planned it all out today. Labor was $200 to run all the lines in 1/2" conduit, about 15 outlets, (2) 3 way switches, 2 outdoor lights, 220v line for welder and 220v line for the air compressor.
Dang... that adds up quick!
Now I have to sell my enclosed snowmobile trailer and all will be well!