I recently bought a unichip on Ebay from a Navy guy who was going 'guess where'. Had to sell his WRX and was dumping the goods, so I paid $525 for a three month old chip. Very impressive improvement - noticable low end torque and builds and holds 2 more psi boost. He also sent along the manual boost control which I will install pretty soon. After I get that dialed in I will post a pre & post chart for rpm vs boost.
BTW, I installed the chip myself pretty easily on my lunch hour at work. Only thing missing from the turbo xs instructions was the bit about the special spacers to refit the cover plate, so I spent about 10 minutes puzzling that out - no biggie.