I agree that a really nice 79 TA should bring a good price. I also agree with the analysis so far. Another reason for the perception of lower value may just be that there hasn't been a history of high prices paid for 79's, and most buyers tend to look at what has been paid for certain cars in the past as a way of deciding value. The high dollar muscle car era cars have that history. Same thing has happened with late 70's Corvettes, I believe. It's good for the buyer who recognizes how much fun these cars can be, but not a good "investment" for owners so far. But, I wouldn't necessarily look at what the price guides say it's worth. I think you could still get a good price. All it takes is one buyer that sees, and really likes and wants your "like new" 79...someone whose desire for your car isn't governed by what somebody else thinks it should be worth...just by what it's worth to him.
While it seems most people like the older TA's better, 79's are my favorite. It's really the only year that I wanted when I decided to buy a TA. Now, I have 3. I liked the new look of them when they came out new, but I had a Corvette at the time. I just buy 'em because I like 'em. That they didn't cost much was a bonus. It would be nice if they go up in value, but it's not the reason I got them. If they never go up in value, it's not that important to me, cause I just like having them, and not interested in selling anyway.
Mine aren't nice yet, like yours apparently is. The 2 that run are still fun to drive in only "junker" condition, and people enjoy seeing and asking about them when I'm out and about. I'll eventually restore one or two of them. Since I can do my own resto work, I won't have a lot of money in them. Doubtful that they'll ever be worth a lot, since they aren't SE's, TATA's, or 4 speed 400's. But, I'll get my value out of them in enjoyment, and by the time I have to part with them(if ever), I won't lose money, since I won't have that much in them. And they probably will have gone up in value by that time.
I've done the same with 73-75 Pontiac A-bodies(73 GA, 73 GTO, and 75 LSC). While they may never be very valuable, I like the style and they also get attention, with people often asking "how much I want for it?". I just tell them, not for sale. But... I might be surprised what somebody would pay, if I actually gave them a price.
Best investment cars I've owned have been 57 Chevy 2 door hardtop BelAirs and Convertibles over the last 30 years. Again, I didn't buy my 57's as investments, but because I bought them when they didn't cost much, I always made good money on every one I owned and eventually sold. And while I love a 57, I'd rather have a 79 TA to drive, and that's just the way it has worked out
.