They are getting rarer these days as the system never really took off at the time.

The problem was that when the 3D0 was released it was definitely more powerful than the 16-bit consoles currently on the market and it's capabilities were near to the first Playstation, but it cost a lot of money so hardly anyone bought one. Plus there were not that many games released for the system.

But they are not so rare that you couldn't find one if you really wanted.