Stage 1 WRX reflash = 205-215whp $300-800
Stage 2 WRX Turbo back exhaust/Intake/uppipe/Reflash = 225-245whp Cost $1500-2400
Stage 3 WRX 18g turbo or 20g turbo/front mount intercoooler/External wastegate/Tgv Delete = 350-400whp $2500-3300 added to ^
Stage 4 WRX hybrid motor using wrx heads and sti 2.5 block with forged internals = 400-550whp $3000-6000 added to ^
everybody has there own kind of stages for WRX's but these are the ones TDS motorsports recomends