The first generation RX-7 (SA/FB) was built in Japan from 1978 through 1985 and someday the surviving cars will be valuable because it fits all the criteria for a collectible classic -- 2 doors, appropriately fast, fun to drive, decent aftermarket support, lots of enthusiasts -- however, I think it is still too soon for the SA/FB to demand significant money...but am I wrong? Find this 1982 Mazda RX-7 here on eBay offered for $10,000 buy-it-now or make-offer. Tip from Greg.
A brief glimpse at recently posted SA/FB RX-7s shows a decent market spread, from the $3000 examples that are likely a few hot shut downs away from low compression crank-and-no-start (the dreaded symptom of rotary engine failure) and then the low mile survivor examples with less than 60k miles on the odometer and the original engine...and that's the rub. Don't be fooled into thinking that the rotary is going to eat your wallet with expensive repairs like a 90s Saab or 2000s Mercedes -- but do budget for a rebuild sometime in the 80k to 120k mile range for a 12A or 13B -- anybody who tells you otherwise has had way too much of the kool-aid.
See a better example of a survivor RX-7 for cheap? firstname.lastname@example.org