Somehow I missed this. $500k is the price of a brand new combine with a gigantic head which obviously wouldn't be appropriate for your place, but if you really want to combine you can do it way cheaper than that as long as you're willing to deal with old machinery. Hell I have a combine I would sell you for $7k (John Deere 7700 from the late 70s sometime with a 24' head). It hasn't been run since 2012 but it was fully functional when I parked it. If you came and got it running and arranged the trucking yourself I'd probably sell it for $5k. Obviously you're not going to come to Montana, but there's plenty of old machines sitting around if you want to make the effort to use them. Plenty of shit that is from the 50's or older is still in use all over the country. It's still not going to be economical, but it's a lot more realistic than buying new.