i'm so happy. i used it 3 times tonight to much success. investing a piece and making a mold that's really, really bubbly if you don't vacuum it right. came out clear as water. (it's a clear molding compound)
overall i think i got out under $30 and about 8 hours of work.
well, it's worth it. i did find out my pump is well over 10 years old, and it probably cost well into $300-400 when it was new.