Auto Parts: 1997 Nissan Altima Transmission Issue, nissan altima, torque converter

Question
I have a 1997 Nissan Altima with 109K miles, which seems to have some transmission issue. It doesn't shift smoothly as expected especially when cold and on uphill slopes. A local transmission mechanic looked at it and concluded this is mostly an internal transmission problem. I was told that the problem was a bad "pump and Torque Converter".

My question is: If these are the only parts needing replacement to fix the issue, does this require  "transmission rebuild"? I was told that just torque converter and pump cannot be replaced without replacing "other" parts through rebuild and I am being charged ~2000 for fixing this. Is this reasonable?

Thanks!

Answer
If I could answer your question with one word - ABSOLUTELY.

A good transmission mechanic will sometimes be able to diagnose the problem from the outside, but not everything.  They'll never know until they get the trans completely apart as to what exactly is wrong and needs repair and/or replacing.  

Think about your car here - originally it was somewhere around $20,000 new, give or take a few correct?  That's only ~10% of the vehicle's original cost.  Yes, transmissions are expensive.  :)