i think it all depends on how long you want it to produce the power for... both how much heat you can get out/before heat soak sets in... and how long till you trash your motor.
 
I've done rebuild with:
forged ceramic coated pistons,
new head, bored 1mm over,
custom exhaust manifold,
GT3076R,
Custom fuel rail,
800CC injectors,
custom inlet
Spearco intercooler
5SFE oil pump
aftermarket ECU
etc.
 
but i only make round 250rwkw... (probably less at the moment cause it's running a tad rough lol)
my main concern was not blowing it up, so it's tuned conservatively and it runs rich... as anyone who's seen me hit my redline will attest from the flames and smoke and such.... I could easily tune it for more, but it really depends what you're building it for? numbers? driveability? reliability?
 
you can probably get the numbers for bragging rights for a lot less $$ but you'll be risking your engine or making it a bitch to drive...
 
my advice on "stages" or progression path would be in line with the "power primer" it tells you a lot about what outputs require what mods as a bare minimum, you can tie a lot of the stuff together by changing the ECU though so i'd skip a lot of the piggyback fiddly stuff and do that earlier than they recommend and save $$ in the long run.

Well I understand that serious power and reliability do not go hand in hand. So my ambition is to gradually get up to say maybe 275-300rwkw, for the only reason of having the power there, and no, I would never trash my engine. I cant think of any other specific need or use for it as i dont plan on racing my car. I would obviously need someone to assist me with this here on the Gold Coast, as my knowledge with all this stuff is limited. I would need to find a proper workshop where they know what the fudge they're doing on MR2's.
Big thanks for the info so far.

To give you an idea on what a parts list looks like for 300+ KW @ wheels here it is from my last MR2. (Some items I have probably forgot)
 
Polished GT35R .82 V-Band housing
Tial 38mm wastegate re-routed
Stock ex manifold
Fujitsubo 3" exhaust
RMR inlet manifold with stock throttle body
Wolfkatz top feed fuel rail with 1000cc Delphi injectors
Walbro pump and Turbosmart FPR800 Fuel Reg
HKS 264 cams with HKS cam gears
Port and polished head with 1mm oversize Ferrera valves
Engle valve springs
L19 headstuds
Eagle rods
CP 86.5mm stroker pistons 2.2L
knife edged lightened 5sfe 2.2L crank
ACL race bearings
ARP main studs
High flow high volume oil pump
VMAX block girdle
Fidanza flywheel
Clutchmasters FX400 clutch
Gen3 gearbox with stock lsd
CRW Upgraded cv joints
Grex oil thermostat
Large side mounted oil cooler
6" K&N filter on a 6" to 4" velocity stack
Tial Q Bov
700x300x100 boot mounted intercooler. Twin 12" fans
AP Engineering Power FC
MSD 6A ignition box
MSD HVC coil
Magnecore KV85 ignition leads
2Ltr Boot mounted oil catch can
PWR alloy radiator
 
Keep in mind the list above does not include:
Custom hoses/brakets/fittings/wiring/intercooler piping/powder coating etc etc
Upgraded brakes (To stop with this power)
Suspension parts
Gauges to monitor the engine
 
I'd say I spent about 20-25K on the engine/driveline and another 15K on suspension/wheels/brakes/interior stuff.
 
Alot of this work was done by myself so if I had gotten a mech to do the lot it would have cost a fortune!
 
Hope this helps :)
Edit: My old showroom thread might have some info on the build http://www.mr2australia.com/mr2play/tm.aspx?&m=7873&high=mrskylighter&mpage=1

Wow, that pretty much details it right down. Pretty amazing work.
How much time would you say you spent on the whole process??

that's probably a tad more than you NEED to do to get the figures.. but again, overbuilt usually = more reliability... unless you're changing stuff that you don't need to.... if you need to change a part from stock then you might as well get a tough part.
 
$20-25k sounds about right if you do a lot yourself.... i spent a lot more than that but did it in stages and had to pay someone else.
 
finding a good mech who knows MR2's is a major factor too... theres lots of guys around who might know the basics or be able to tune them but doesn't REALLY know mr2s... try and get hold of the queensland club and look at going to brisbane or over the border to NSW rather than stay local with someone who's "willing to give it a go".... i've had my fare share of ****ty mechs and it's probably cost $20k cause of them alone.

Well when you get to the point where you know that your going way over the top with the build, a second car to be used for daily purposes is required.
Then the MR2 will live either in a mechanics workshop and/or your garage whilst the building (Spending) is taking place. I'd say a couple of years for my build with a bit of driving it in between :)
I probably started buying parts for the build 6-9 months out from the start
I was researching for years before I decided to do it.
 

sredze

Wow, that pretty much details it right down. Pretty amazing work.
How much time would you say you spent on the whole process??

If you want a reliable motor with more than about 260rwkw, you should budget for AT LEAST ~$15k in parts, usually closer to $20k-$25k or more, as others have said above.
 
That's just the parts. If you do all the work yourself you will save a huge amount of money, but it will take much longer, and require experience and confidence to get it right.
If you get a decent workshop to do ALL of the work for you, the overall cost will roughly double due to labour costs.
 
In my case, I did about 10% of the work (eg. electrical stuff like wiring up the ECU), and a workshop did the rest, so the labour costs were very high.
I have always had a second car for daily driving, so it wasn't a big problem having my MR2 off the road. However, even with my MR2 at a workshop and being worked on fairly consistently, it still took about a year to be 'completed', plus an additional 4-6 months when I had to change some stuff and get an engineering certificate for all the mods.
 
If you purchased ALL required parts before you started the work (not likely), you would probably shave many months off the total completion time, however, it is very unlikely that you will go through the whole build process without changing your mind about some things.

Well I right now I am probably in the researching/planing stage. Trying to to set out time frames with ideas on what exactly I plan on doing. Plus I have the bonus of all you're experience and expertise on these boards. Knowing what kind of budget is needed is another bonus from all this. My main thing is also going to be finding a capable workshop who will do all the labour as I am really time strapped due to work commitments. But all this helps a lot. I guess 25-30k should cover me. Will take a lot of saving though over the next couple of years.

if workshops are doing all the labour you need to add that to your cost. so far we just talked parts. figure in a couple of grand at least every time you have to drop the motor... so it's cheapest to do it in one go. 
 
my motors been out twice and i did it in stages and the bill is somewhere over $60k so far... but that includes a new gearbox from toyota for about $5k..... custom piping fabrication, a couple of tunes on the dyno etc. if you just bought available parts and did it in one hit you could save on some labour... 
 
I've stopped counting.

...MR2 Turbo = gaping money pit :P