Engine rebuild or not?

I agree with the above answer. The rotary has very little moving parts, but the real secret is in the setting of the wipers in the impellers and the wear patterns in the side panels. Used is somebody else's problems, and if you rebuild it the points above. Try finding a reliable supplier for a rebuild and trade in your old engine. The chances are rebuilding one of these things is above the dealer. Mazda wants to sell them a new engine to sell to you. These are all probably more expensive than what you might expect for a piston engine, but if you like the car and engine it might be worth it. I liked my RX-7 and after a few mod's to the engine it ran even better with a custom built fuel injection.

i agree also or you can buy used engine if liked to cheaper way. speak to a good junkyard , normally they sell good used engine.