I’m in the middle of building one of these types of Quonset huts. Mines 40x80x20. The base plates were right at 5200 and the end kits I’ve priced were around 3k each. The building itself I think was around 40-45k when the original owner bought it in 2017 so adjust for inflation. My father in law ended up with the building (unassembled) after the original owner had some debt issues. He gave it to me after he sold his business.

I’d estimate the cost of the one the OP is asking about is probably around 35-40k.

For anyone thinking about getting one of these buildings, pay someone to put it up for you. You can build these with some help, but trust me, pay the man and save yourself the trouble. I’m about to contract out the remainder of the build once I wrap up a few things on the base of the building.