SO I found a 1993 RX-7 with 79,000 miles on it, but ONLY 8,000 miles ON THE NEW ENGINE for $7,000 OBO. It already has a cracked rotor, but without looking at it, I cant tell which one it is. My questions would be:

Is it worth replacing just a rotor?
How about replacing all of the rotors with aftermarket rotors that last longer?
Can I just replace a rotor or do I have to look at other things like where the rotor sits?
I wouldn't have to replace the engine again would I?
Is it safe to drive with a cracked rotor for about 250 miles?

I wouldnt have the car on the road for another two years though because I cant afford to as I am going through school. Im not fretting as I have another car to drive in the meantime. I am planning on working on the car within the two years and storing it in the meantime.

Any ideas on where to go from here?