Make sure that the 90k mile service has been done on this car you're checkin out. My guess is it hasn't. Think about it. The prior owner probably took it in for an estimate and heard how much it costs for a timing belt, water pump, etc etc and decided to trade it in. Why else would the advertised price be so far below blue book already? That service right there can easily run you up a huge bill. If the clutch hasn't been replaced yet there's probably not a lot of life left in it. The CV boots might be on their way out. The shocks are probably done. Also the power steering pump on the G2's is notoriously failure-prone. Let's see, what else...oxygen sensor is probably old, as is the fuel filter. Oh and you'll love filling up with 91 octane or better. Sure you'll get like 25 miles to the gallon, but it's only a 13-gallon tank.
I learned all this the hard way--the car I bought (this was a couple years ago) had like 62k miles on it and the 60k mile service hadn't been taken care of. I was so set on getting the car because I got caught up in all of the hype about it being the rarest Integra ever blah blah blah and didn't plan ahead on the expenses I'd be incurring.
Generally speaking it's smart to leave money in the bank when you make any sort of big purchase, especially something like a car that's going to suck up a bunch of extra funds. Get the car checked out and if the 90k mile service hasn't been done yet, stay away unless you can get the price below 3 grand.