Google is our friend lol.
"
http://en.wikipedia.org/wiki/Mazda_RX-7 "
normally you get what you pay for. if the price is so low, it might have some issues. i would recommend looking at it closely and if you have a friend that is rotary capable, bringing him to see the car. also go on
http://www.rx7club.com/ and this forum and look around. rx7 tend to be very expensive to fix look around for information. know what your getting your self into. A FD and a 240sx" not a Silvia" are two different cars