Reasonable price tire changing machines?

I've been wanting to find a used tire changer for several years but damn they're expensive. I'm too damn cheap to pay the tire stores 8-10 dollars to get a tire mounted or dismounted so I've always done them myself. The day before yesterday I pulled eight tires off the rims (four '84 rims and the four ARE rims in my avatar), and then re-mounted the four track tires on the other set of wheels. I've been doing it manually the past couple decades on a fixture I welded up years ago, and while it works pretty well, it's not fun on a 90 degree day, and it's obviously slower than what a modern, powered machine can do. Just curious if anyone has any suggestions on the best places to look to find a decent machine for personal shop use at a reasonable price.

Thanks,
Mike