Model 80 recirculating toilet

Okay, so the toilet went belly up........it was original to "the manor house", so 20 years is a pretty good run, in my opinion. the problem is I CANNOT AFFORD 600.00 for a new toilet..........does anyone know where I can get one that isn't going to require me to sell a kidney to afford???

Is there another recirculating toilet on the market that can be switched out for this model????