Love old Pontiacs Joe! I had a '68 Firebird in high school and recently helped my good friend buy one for his classic car collection...

Obviously, this is a Gen 1 F-bird, but has a 400 small block and runs great!
Condition is everything when considering buying a vintage car. Do a little research and see what others are listed for, I listed a couple below. We typically search out cars that have good paintwork, painting a vintage car is very expensive these days [easily $7-10K].
Internet pricing such as Kelly Bluebook is nearly useless, bottom line the car is worth what someone is willing to pay. Matching numbers is a premium, if it is advertised as such, learn how to check for it.
Bring a big magnet and check for thick bondo. We nearly always get it on a lift to check the undercarriage for rust.
Most auto repair shops will do a pre-purchase inspection for $50-100 bucks. Worth it.[found a '69 F-bird that had a swiss cheese frame! Obviously, we didnt buy]
Go see the car, get a good feel for it and the seller. Has it been maintained and have service records? Take a long drive, at least 30 min, many issues may pop up within this time frame. Overheating, not re-starting, alternator not charging, transmission slipping, etc.
The '74 is a very desirable car, especially with the 455!
Here's a couple that I found rather quickly. I personally wouldnt pursue the first red one..
https://hudsonvalley.craigslist.org/cto/d/poughquag-1974-pontiac-trans-am-455/7118584647.htmlhttps://www.ebay.com/itm/1974-Pontiac-Trans-AM-Super-Duty/124195211636?hash=item1cea9c8974:g:1koAAOSw3PpexpBwGood luck!