There is soooo much more to “just a turbo upgrade” and swapping out a snail.
And on an engine that blows up on stock turbos with bolt ons and agressive tunes, even a bigger turbo (and supporting hardware) with a lax tune will still be pushing the limits hardcore with that motor.
Big turboing a subaru is more an all or nothing comitment than many other platforms. The turbo may be only $700, but the injectors, fuel pump, up pipe, down pipe, wastegate, intercooler, charge piping, tune, oil & coolant lines, etc cost 2-3 times that to get it running. Then cross your fingers the ringlands done crack off and take the bottom end out and make you drop another $2000+ in parts and machine work. Then clutch and flywheel to hold the power.
Its a shitty cat and mouse game. If you are not prepaired to just cut to the chase and shoot the mouse with a shot gun as soon as you see it, you will hate battle.