It's a bit sad that they couldn't squeeze that other 100,000 dollars for a new explosion out of the production. That all went into the redesigned uniforms they never used.
"Generations" is a funny fish. It doesn't really look
like one of the cheap Trek movies, certainly it had a modest budget but it wasn't exactly a tightening of the belt. But it did face some major budgetary problems, because mistakes were made along the way in where exactly they spent all that money. Bafflingly, most of it seemed to be elementary mistakes. Things like (as you say) spending all that money on stitching together uniforms that were scraped after filming began, or having to go back and reshoot the ending because the original version stank, or shooting elaborate stunt sequences (orbital skydiving) which didn't even make it into the picture... these are mistakes that somebody with a bit more experience in movie production might not have made. They could have nipped it in the bud during script conferences, but for some reason a lot of these problems ended up being fixed during
production, while the cameras were actually rolling. Maybe it was because they didn't get a whole lot of lead-in time from finishing up the TNG series? Who knows.
I always got the feeling that Berman, Moore, Braga and co had the training wheels on during "Generations". They were really feeling their way through the process of making a feature movie, and that they took a lot of lessons they learnt from the experience of making it into the next one. Hence why "First Contact" hit all the right beats straight outta the gate...