help me pls. i have a toyota corolla 89 model, when i tried to shift the gear in 3rd gear it has a weird sound and somtimes it does not enter the 3rd gear, i went to some mechanic to consult the problem they told me i have to replace the transmission of my car, they told me it is repairable but they advised me it is better if i replaced the whole transmission device..

i look for a surplus of a transmission device and it cost about 9k without the labor.. need help should i buy a transmission or anyone here know where could i bring may car for the repair of transmission..please help