I find it funny that they changed the uniforms for a single episode, but when it came to Generations, a MOVIE, they settled for random TNG and DS9 uniforms right off the rack. It's odd there's never been clear footage of the aborted Generations uniform. The only remnant I've seen are the action figures and a scratchy VHS deleted scene.
Oh, but they did make new uniforms for the whole cast. Sure, they weren't Starfleet uniforms and they were only used for 10 minutes for a scene that was stupid and pointless to begin with....
I think it had less to do with the movie being cheap and more to do with the producers making the worst budget choices ever.