Most of the first Gen Gundam kits are sloppy. Their engineering was somewhat bleh from the time, and the proportions try to reflect that of the TV show, but I find that even then, it's often too stocky.
The smaller kits IMO aren't worth getting. I'd say that none of the older run kits are. I hear that the Magella tank, most of the large capital ships are really nice... so maybe. The MA availible may be worth the while, seeing as how they probably will never see re-release in another line.
I don't believe that affordability should be the issue here, as most of the kits are cheap to begin with in any Bandai line (in compare to FSS ^_^) it's not really worth the time and effort to correct such kits. Mind you, I own about four of these kits myself (all mecha) and of designs that aren't yet redone (such as the Gyan). I fully intend to complete them, but I certainly do not recommend them to a casual modeller.