Agree with [MENTION=18194]Honcho[/MENTION] and [MENTION=26435]Old Guy[/MENTION].
For all the maintenance, I would go after dropping the selling price vice having the seller address it and then sell you the car. If for no other reason, the work will be done at a shop under your name for warranty purposes and "call back" purposes if something wasn't done right. Unless the car/shop is local, it doesn't do you any good once you own the car that will be sold "as is" (probably) if the shop that "fixed" it is 4 states away...
Here are some things to consider:
1) The A/C unit is R-12. That can be expensive and sometimes hard to get. Conversion to R-134a can be done, but first you need to find out where the old A/C refrigerant "went". I would have a PPI done and have them put an A/C gauge manifold on the system and check pressures. The issue could also be the A/C compressor clutch is not engaging...either way, budget for that repair. The other reason the A/C many not be working is the Climate Control Unit may need to be repaired. See the discussion below about capacitors (I thought of this cause and added after I wrote the rest)
2) Timing belt never being replaced is a HUGE red flag to me. What other maintenance has been blown off? I would suspect the spark plugs have never been changed, the fuel filter has never been changed, the coolant probably hasn't been flushed and, the valve lash has probably never been checked, the brake fluid probably hasn't been flushed, and CERTAINLY, those hoses are 29-30 years old. That is a 90K+60K service plus coolant hoses...that will run you - if a shop does it - probably $5000-$6000 (my best guess, haven't run the parts costs and depends on the labor rate...if you go to an Acura dealer that still has a certified technician, expect to pay $150-$200/your in labor...and you bill could suddenly be a few thousand higher than my "spitball" estimate
3) The radio. First you need to figure out if it is the head unit or the speaker amps or just a fuse. I would first check all the fuses. If the head unit doesn't work, and you want to stay OEM, that is a $3000+ part from Acura. A repair - if you can find a shop (Willman's used to repair the factory head units, but now they do a modification and put new guts into the old radio to give you BT and other "modern" features) - will set you back hundreds. Used head units occasionally pop up on the market, but that is a crap shoot. Aftermarket head units are cheap, but the center console modification is where the cost starts to escalate. If the head unit works but the problem is a popping/static sound from the speakers, that is the Bose amplifiers on the speakers (NSX uses individual amplifiers at the speakers not an amplifier in the head unit). Brian Kiehnau at NSX E-repair (see link here:
http://www.nsxprime.com/forum/showt...to-new-NSX-Owners-(and-maybe-some-not-so-new)) can fix these fairly cheap (few hundred dollars for all 3 amps)
4) If the warning that is lighting up is the "BRAKE LAMP" warning in the little car shaped indicator panel at the bottom center of the instrument cluster, then that can be an indication of the instrument cluster needing to be repaired (again, another job for Brian Kiehnau) as this is one of the first signs of capacitors leaking on the circuit board (more below on this) and if left unaddressed, could result in significant damage up to and including the instrument cluster catching fire.
5) Tires can be a challenge for the 91-93 OEM "Fat Five" wheels. There are limited options out there for the 15/16 (205/50-15 and 225/50-16 tires) setup. Tire Rack will show you a total of 10 tire sets..3 are track only. The other 7 are summer tires. A set of the summer tires will run you between $400-$625 depending on the brand/tires. The track/autocross only tires will run you $800-$1000 a set.
Capacitors. This is a function of the capacitor technology of the late 80s/early 90s. The are now starting to break down and leak. The leakage damages the printed circuit boards (PCBs). This isn't unique to the NSX or Honda/Acuras...this is a function of technology, so I'm sure the Supras, RX-7s, etc, of the same era are probably going to see, if they aren't already, similar issues. The capacitors are located in most of the electronic components - but the Climate Control Unit, the stereo head unit, the instrument cluster, the SRS unit are where the majority of issues are being seen. Brian fixes all but the stereo head unit right now. I can't speak for the ECU, TCS, or ALB boxes. But this phenomenon is something to keep in mind as the repairs - based on the TB/WP red flag - may be coming due.
Without seeing the car, but seeing the reading the issues with the car, I wouldn't be willing to spend more than $45-$50K knowing the amount of work that will be involved in sorting out these issues. A/C can become a big money pit. Catching up the maintenance (TB/WP definitely...I would be pretty nervous driving the car until that got sorted out), fixing the stereo and sorting out the other small issues (plus knowing you need to buy new tires right away) could leave you staring down the barrel of $10K in costs...and at the end of the day, sales price history (this is right where the historical "asking" price is for 50K miles - $60K) shows 50K NSXs are selling for $55K...minus $5K-$10K in repairs needed...
