Another newbie ZR-1 question

[Z R 1]

Hello everyone,
I am very close to buying a polo green 91 ZR-1 w/38k (all stock) in the 20k range. I currently own a 78 and am bored with it's lack of power and decided to look for something with not only more zing but something that also has collect ability. I was very close to buying a 69 coupe 350/350 when I found this ZR-1 that was the same price. I really like the ZR-1 and am very impressed by it. The only thing that is holding be mack is wondering if my 20K that I put into buying this what will the market value be in like 5-10 years? I don't plan on driving it daily but I also don't believe in just letting it sit either? I know it will need things and probably one of the first I would do with a full tune up is replace the injectors with some RC's. I have read some that these cars could be very highly collectible and then others that think it will become just a foot note and never be very collectible? Any advise on putting 20K into a ZR-1 instead of a 69 Coupe would be greatly appreciated!