I bought a used bead seater tank 4-5 years ago off FB Marketplace for $40, only thing wrong with it was the bent handle. The only reason the guy was selling it was to get a larger one for large truck tires.
The frustration and time it has saved me was well worth it, especially for the front tires on my lawn tractors. I've used it more times than I can remember although maybe only 5-6 times a year including neighbors & friends.
Even got a deal on a used rear tine tiller because the guy couldn't get the bead back on, on one tire. He dropped the price, so I paid him. Told him I'd be right back, had to get an air tank out of the truck. He told me he had an air compressor and had worked for 2-3 hours to get it mounted and gave up and why the reduced price. He looked puzzled when I came walking back with the bead seater tank. I asked him if he could rock it up on the other tire and said sure. I placed the snout on the rim and WHOOF..!!, bead was seated. He looked at me and said SOB..., I gotta' get me one of those and laughed. Money he knocked off the price of the tiller more than paid for the tank right there.