Hi bro as per your PM to me, better we converse here so that it's more transparent. The prices below are guesstimates should you wish to source your own parts and are as what I've seen on mudah:
*Auto box with torque converter - about 1000 bux
*Prop shaft aka long shaft - 150 bux (can use your manual shaft but gotta cut shorter and balance)
*Differential - 700 bux (can't use back manual one)
Don't know the costs for the wiring and other cockpit parts. As I'm a parts-noob, other sifus welcome to correct my estimates of costs
.
My own personal advise is to find a swap partner as John_Smith alluded to, or failing that, sell the car! After selling the manual car and getting one with automatic, you might be in the money hehehe!
I just gotta say, you having a manual car to start with makes me delirious with envy
! All the best!