I know they did a sled pull in Weiser (small town near my farm) last year. Let me see if I can find out who ran that event and what they would rent the sled for.
I am surprised it is that much for Firebird. When I get my truck back with the compounds (been in the shop since January, oof) I will talk to the staff at Firebird and see what they can do for a full-day rental. It might make more sense that way. Probably still thousands of dollars because you have to pay for the medics, fire crew, track prep, etc. But at least that way we could run all day.