How much does an ecu replacement or repair cost?

I have an automatic 1992 mitsubishi 3000gt that has problems shifting to second because of the ecu... how would i fix it or how much would it cost for a mechanic to fix? or could i just buy a replacement?How much does an ecu replacement or repair cost?highly unlikely the ecu would cause that problem , you can buy used ones from mitsubishi specialists, is it the twin turbo? great carsHow much does an ecu replacement or repair cost?280 dollars or so for a rebuilt one