My thai gym used to have one before we took it over.
It had loads of shit gear but I said to them if they wanted to clear everything out I would buy it off them.
It was a old leather padded one. Excellent for back extensions and weighted ab work because the padding was right in the position it needed to be.
They threw it out one weekend when I wasn't about.
Be sure to try the roman chair out before purchase. Its definitely needed to buy an adjustable roman chair to adjust for long/short legs/torsos and most of all, many badly constructed RC tends to crush your balls.