2000 honda civic dx 5 speed making funny noise?

I took it to the shop and they said I need a new transmission and clutch. I took it to a friend who said all I need is a release bearing.

It makes a growling/grinding noise when I hit the accelerator. When I push the clutch in or let off the gas, the noise goes away. I just bought the car and thought it was something else. Any ideas?

That does not sound like clutch or release bearing. That sounds like an internal bearing in the transmission. Try changing your gear oil and make sure it is all the way full.