Really not sure. It comes down to what you're willing to pay. I personally stay away older cars with ridiculously low miles. Mostly because of swapped odometers, but also because I assume they've been sitting for years without being started or maintained. The rubber components are designed to be used.
Regardless, assuming it's low miles, good condition, not a rust bucket like everything else in NJ I'd guess somewhere between 7-10k. It's still an older car. It's not going to maintain its value or appreciate like a low mileage/well maintained NSX.
And what cleaning up could it need? Doesn't sound like the owner's drove it enough to even forget anything in it, spill anything, scratch it, etc.