How often do you have to get a new transmission?

Back 5 yrs ago, I got a new transmission for my 1999 plymouth grand voyager SE, and now today they want to put a new one in again. Do I really need another new transmission? Back 5 yrs ago it cost me $2000 and now they want $1450. I am unemployed but I need my car to go places and to get a job, suggestions or if you need more info contact me. Thank you,
RuthK