If a deal is too good to be true, it probably is .
An Rx8 with rotary & 30k original miles is highly suspect, take your time, do your research, if you do decide to buy it don't forget to gets its engines compression checked as well as its frame for any accidental repairs , with the permission of owner, if owner doesn't allow this then that in itself is a red flag , and should be reason enough to walk away.
As Capsat said verification of registration is even more critical matter , take it very seriously.