very well said on both points for david and andrew. my gtr has been a 'rebuild in progress' aka pretty much when something looks like its getting worn and needs replacing, I'll do the entire surrounding stuff just for the convenience and peace of mind (eg when my radiator needed a clean, I bought an upgraded radiator (isc 52mm), new rad hose, fitted the n1 water pump i'd bought off pete, changed the timing belt, pulleys and seals and topped it all up with nismo coolant)
its fun if you like to modify and you like to know every little detail about your car (like I do) but it can be expensive - generally tho its a lot cheaper to get in before something breaks and causes even more damage - ceramic turbos being a case too, i still have ceramics but antimatter is going to rebuild a spare set with n1 steel turbines and new bearings, so not only will I have peace of mind about the turbos once theyre fitted, I'll also be able to dial in more boost.... win win scenario really)
And then its the suspension, hicas fix, interior retrim, dump pipes and cat, sump and head baffle/journal plates, etc etc etc
gotta love gtr's
-D