I'd suggest find a written off car at auction with reasonable k's  on it and swapping the engine over - thats if budget is the main factor. A lot of the time the cars are still drivable so you can test the engine fully before you pull it out (but not before purchase at auction) Could find an engine being sold thats still in a car being sold privately with the right timing if you're lucky enough. Can't imagine they'd be worth a fortune.
 
The 3sge is normally a really reliable motor unless it has been badly abused. No need for engineers certs, its a like for like swap. Would need the engine no's changed though through your state car registry. 

No Phiz, I got no idea on how to take out myself lol

Thank you so much Mister2, you save me a lot of time n money wasted ta

Thank you Dudeman, I guess my wise option is to rebuild my own engine n hopefully it's last another couple 100ks

Cash
Hi all,
Does anyone know n can recommend an experience mr2 mechanic in Melbourne. I am thinking of rebuild my 2. 1997 N/A ADM GT. and roughly cost of rebuilding it. Ta

I not long ago rebuilt my 3sge engine completely, did it for MTC 2016 just gone, so you have an idea, I rebuilt it with all genuine toyota parts (where ever I could).
Here was my parts list if it helps:
 
Full gasket set,
Oil pump
Water pump
Main bearings
Con rod bearings & bushes
Pistons & rings
Timing belt kit
Clutch kit
Head bolts
 
Machined parts:
Block faced
Cylinder head - pressure tested & faced, valves lapped in & assembled
Block honed
Flywheel faced
 
This all came up to around the $2500 mark. 
 

Thank you Carmikey, did you rebuild it urself? If not which mechanic did you use? and does the 2 gain any power compare to before you rebuild? Ta

Carmikey

Cash
Hi all,
Does anyone know n can recommend an experience mr2 mechanic in Melbourne. I am thinking of rebuild my 2. 1997 N/A ADM GT. and roughly cost of rebuilding it. Ta

I not long ago rebuilt my 3sge engine completely, did it for MTC 2016 just gone, so you have an idea, I rebuilt it with all genuine toyota parts (where ever I could).
Here was my parts list if it helps:
 
Full gasket set,
Oil pump
Water pump
Main bearings
Con rod bearings & bushes
Pistons & rings
Timing belt kit
Clutch kit
Head bolts
 
Machined parts:
Block faced
Cylinder head - pressure tested & faced, valves lapped in & assembled
Block honed
Flywheel faced
 
This all came up to around the $2500 mark. 

 
I recently did my own Gen 2 motor with virtually the same list as above, and the cost was similar.
I saved a lot by doing most the work myself, but that should give an idea of the cost of parts and machining work if done properly.
I also agree about the importance of using genuine Toyota parts if possible.

Cash
Thank you Carmikey, did you rebuild it urself? If not which mechanic did you use? and does the 2 gain any power compare to before you rebuild? Ta

Yeah did it all myself minus the machining work.
If your looking at getting someone else to do the job (a shop or mechanic) I would assume you could almost double that 2.5K.
In regards to power gain, yes there would have been an increase, but probably only detectable on dyno, honestly I would like to say... wow, there was a massive power increase, but unfortunatley not.. but it did sound solid, tight & was very responsive.

Double. That worth more then my 2 lol are you anywhere near me Carmikey? If you r care to do a love job for my 2 lol anyway thank you for all the inputs

Cash
Double. That worth more then my 2 lol are you anywhere near me Carmikey? If you r care to do a love job for my 2 lol anyway thank you for all the inputs

Mate, I'd be happy to rebuild it for you, but unfortunately I'm located in Adelaide.