That is an interesting and unusual rig, it will attract attention at a show. It's priced for a rich collector, not someone who wants to use it. The seller probably does not have over $2000 invested in it. It's small enough to haul to shows if you can find a way to lower and raise the the elevator easily. The odd wheel spacing and tire directions make it a bit questionable, like it was assembled but never setup to use in a field. I'm surprised there is no divider around the front wheels, or any side screen to keep trash off the engine and ignition.
I'd do a lot of homework before even considering making an offer on it. Maybe even buy a manual for the picker to verify if all the parts are there, you can always resell the manual afterwards. The research might be as much fun as actually owning it.