creative solutions to subcompact tractor tires

my little kubota needs new rear tires (29x12x15), but the problem is, when you jump from a lawnmower/garden tractor tire size to a subcompact size, things seem to jump up in price a lot (i'm sure the quality goes up too.) This has me thinking about what other options for rubber are out there. There are AT truck tires in that size, but they're about the same price as the tractor tires. UTV tires would be my next choice but the seem to come in a max of 10 inch wide, which I might be able to stretch onto the wheel and still be usable. If it comes down to it I'll just pay for the tractor tires, the ones on there did last a few decades so it could be worse, but I'd appreciate any suggestions. 

Used AT truck tires? Wouldn't matter much on a tractor if they are too old to use on the street.

In reply to EvanB :

Might be hard to find used ones in that size but if I found that would probably be the best option

 edit:  actually finding a good amount of used 33s and 32s in the right rim diameter and width. Will have to do some measurements to see if they'll fit, though. Having a bit extra speed in 1 Hi would be good for mowing