Highflo, injectors pump tune etc, is what, 5K?
GTR is 20K, boost T and its making probably 30-50kw less, but has AWD, (more weight) and suspension will be stock, not adjustable. and for 20K you're not getting a pristine one unfortunately. Parts don't break any more than a GTS-t will, but when they do more money potentially, and upgrades do aswell. Twice the turbos, twice the diffs, etc.
End of the day look at how much your saving and how quickly, and if you're prepared to get a loan to get one.
Or, do HA and instrumentation courses and come work out here for pornstar money.