If somone is charging 10995 for a 93 rx-7 turbo with a rebuilt engine...should I be worried?

That depends on the other aspects of the car. These days that's a pretty standard price if the car is otherwise stock, especially if it has high mileage. I got mine for $15k with a brand new engine and about $6k worth of upgrades, but it had 90k miles on it, too. Can you post more details on the car? What color is it, how many miles does it have, what's the condition of the paint and the interior, does it have any other mods, who rebuilt the engine, etc.? These are all things you should ask if you don't already know. IMO you can't go by book value on these cars at all...aside from the normal factors, you have to look at several things specific to FDs.

Just make sure you get it inspected before you buy. This is really the only way to know what you are buying.

I was going to advise that too, but unfortunately there aren't many shops that know enough about these cars to properly inspect them. Definitely not in Longmont (where the car is for sale)...but if you are able to get it down to Denver, have Precision Import Repair or Speed Image take a look at it.