Probably depends on the parts you're looking for. I have an 818 of the latest vintage and have seen some of the prices paid for parts by the company that last owned it. Bourne and Koch has some parts, probably will make or sub out others to be made. Quite high priced, to say the least. I was especially outraged at the cost of a few simple gaskets. Something like $65 *apiece.* I made my own for about $2 worth of gasket material and 5 minutes of time.
They (B&K) aren't real keen on sharing information either. I called and asked if I could get some part dimensions to check if they were worn out (pistons, valve spools, etc.) and was told that that was "proprietary" information, if I wanted to know that I had to disassemble the machine and ship them any parts to check. Then they'd tell me if they were worn out and I would have to pay to get them shipped back. (Wonder what that would cost? $5k?) Pretty GD ridiculous. I put the guy on blast and told him no problem, I'll do my own rework if you guys have that attitude.