150 miles is no big deal to drive a tractor IF there is a decent route.  Tire wear wouldn't worry me much, I'd be more worried about the condition of the tires and if they're likely to make it home without a flat.

That said, $500 is really cheap to get it hauled home IF its going to get done on a time frame that is acceptable for when you need it.    That kind of rate is almost certainly dependent on the truck being loaded both ways and that doesn't always happen on the same time frame as you would like.