building a 11 sec gtr is not that expensive, but 10 sec is.
the maintance of a 10 sec car is scary.
btw,11 sec is more than enough and will be a big different again with yr commie.
low to mid 11 sec - 2 x GT2530 tubro, intercooler, cams + cams gear, gasket, full exhaust system, injectors, fuel pump, Power Fc, clutch (somewhere around $20000-25000 )
not that much as i guess u have to spend similar or more to bring yr LS1 to 12.2 sec