He mentioned he went through a divorce and started his own company, he said it was well maintained up to the point that he parked it. He said the only thing wrong at that point was the power antenna had stopped working for the second time. He also has a 1991 motorcycle with only 1,000 miles on it. So it looks like he bought a lot of toys in 1991 but then stopped playing with them for some reason.
That reason smells like a steaming pile of crap! Lots of people get divorced and start a business and don't let a 'well maintained' NSX sit there and rot into the Earth. Hell, if anything, he would SELL it to raise capital for the business, or his ex-wife probably would have gone after it, but not just let it go. What the heck does he park in the garage anyway if that sat outside for 6 years??
To give you a quick set of numbers that this guy must grab reality with:
1.) Top quality paint job ~ $7,000 - $10,000
2.) A/C repair ~ $3,500 (I just spent $2,000 on mine, and I really maintain it)
3.) Timing belt/Water Pump/Accessory belts/ 90k ~ $2,300 (that's IF it runs. If it does NOT run, you can spend $12,000 on JUST the engine rebuild alone)
4.) Full flush of ALL fluids ~ $700 (assuming the pumps and such still work)
Okay...that is only (4) things, and we are already at between $13,500 - $16,500 and that is without touching the split seats, brakes, or any of the items like clutch master cylinder, brake master cylinder, or any of the several other parts of the car that wear like CV boots, coolant hoses, etc.
Now, I am all for saving a car, and hope that you get it, but you better buy it cheaply. The miles really mean nothing on this car, no matter what the guy says, because you are essentially starting over. None of his maintenance records matter, because anything he did previously is long past needing done again. If you pay a dime over $10,000 for that car, you better be keeping it for a while, because you will be upside down if you want to sell it in anywhere near reasonable condition.
Good luck...just be careful. If you really want to get his attention (assuming he does not take your offer), have the car taken to the Acura dealer (on a flat bed) and let THEM run him a huge estimate on a bill. They would be at $20,000 in work in no time flat.
I walk the walk too. I did this almost a year ago when I was trying to rescue an NSX that sat in a yard for over 6 years. I flat bedded it to a shop and they stopped counting when they hit $15,000 just to make it 'drivable'. That was without touching ANYTHING cosmetic, or other items you would want to fix if you really wanted to use it.
who leaves a car like that in thier yard
there has to be a lot more to that story...
THAT JUST SUCKS! 
