transmission

I have a 1998 chevy malibu ls. I need a transmission but what I want to know is does it cost more if you have more or less gears to replace or does that sound silly. I have reverse and the first gear and thats it. I was wondering would it be more or less expensive to repair. How does it work? It is an automatic. When ever I drive and it shifts at 20 it doesnt shift anymore. It does go in reverse. So I was wondering does it cost more to repair it in that situation. Is it more expensive or does it matter?

A trans shop can scan the trans and determine a diagnosis, may be an electrical problem with the solenoids and not a complete overhaul.

A trans shop can scan the trans and determine a diagnosis, may be an electrical problem with the solenoids and not a complete overhaul. IT COULD BE THE SOLENOIDS EVEN THO IT WONT SHIFT AGAIN AFTER 20?

Usually a code will be in the pcm, but the scan will reveal whats happening, also check for vacuum at the modulator, if equipped, lower l/s of trans.