When you realize that of the 60 million budget for Nemesis, 2 thirds went to Berman, Baird, Stewart, Spiner and Logan, and only 1 third was used for the actual production of the film, you get an idea why big tentpole films are so expensive.
Wow. Maybe thats another reason why there were no more TNG movies after NEM. The guys priced themselves out of the market.
When you compare TMP to STID you've got to include DVD/netflix/cable/etc sales or its not really a fair assessment. When TMP was shown, hardly anyone went out and bought the VHS. If you didn't see it at the box office you might not see the movie for a long time. Nowadays you can see the movie just months after the movie is finished at the cinema.
Also I'm not convinced studios are majorly concerned about ratios. I mean if ST09 makes say $500 million profit and TWOK makes say $200 million adjusted for inflation, maybe the studio says wow TWOK was a much better investment as it only cost $29 million to make or maybe they say ST09 made twice as much money as TWOK. I don't know.