I looked into a few companies last yr for a 3 bay pole barn/garage.
I found it a bit cheaper to let the local builder just put up a garage built like a pole barn on a slab.
The savings were in shipping, upgrades needed for snow weight regulations etc.
If you have a local builder/contractor ask him to figure up an estimate using specs that the kit would consist of.
I ended up actually getting a better built bldg for less $$, excluding the upgrades I asked for.