This is a car I was tempted to buy several years ago, a real odd ball considering it was originally Sold In Arizona with no A/C & Clear Glass. It is a very rare and very solid car. What killed the deal for me was to Color Combo. I really do not like Green Cars. But I love Manual Transmission's behind 400 or 455 4bbls. This car has the 400 4bbl, M-40 Muncie, Bucket Seats, Power Brakes & Steering, Gauge Package with Tack and Clock, Sport Mirrors, Honey Comb Wheels, HD Cooling, Tilt, and Cruise. It Does have the normal falling apart flexible nose, but comes with a fiberglass replacement. 5 or so years ago a different seller was asking $6000 without the new Nose, the present seller has added HEI ignition Interesting car, but will have to find the right buyer. http://www.ebay.com/itm/222318272930
Here's another of these very rare Pontiacs. And this one has AC. http://www.ebay.com/itm/1974-Pontiac-Grand-Am-/142444817918?_trksid=p2141725.m3641.l6368
He might have left out A/C, in order to keep the vehicle as light as possible, for reasons of handling and performance. Power window mechanisms are also heavy. Big deal. So, drive the car in the evening. The color is indeed an eyesore, as you state. Maybe, you could bargain down, using that argument. Then, tailor the appearance to your preference. The rarity of this car should, in any case, pull a good price.
Had not read the full story on the silver one when I posted. For the price the seller wants, if I were a buyer I would want the AC up and working.