Gotta pay to play, guys, unless you can convince SOA that the part was always faulty or they just appreciate your loyalty enough to cover the cost of repair.
I would advise never touching the engine with aftermarket parts unless you're prepared to pay for the (potentially) costly repairs right away or are willing to go without a car for a while. If it's your daily driver, I wouldn't bother.
With my 2011 WRX, it was my daily driver. With my BRZ, it's not quite so critical if I mod the BRZ and it goes down for a bit. I purchased it so that I COULD mod it and race it, basically.
I would add a cold air intake to a 2.0i Impreza before going to pulleys. Also an exhaust would do you good. Suspension tweaks and weight loss would help make your car FEEL faster, for sure. There are so many things I'd do before swapping out the pulley. Just my $0.02.