$439 to $529 regular, $330 to $396 after the 25% based on the website prices (
Snow Performance ).
When jrandol and I set up the last GP, they were $330 across the board, but there have been some improvements since then.
The system works! When you figure on average you pay $10 per 1 hp gain (up to 550 at the wheels then it gets a little more expensive) this system is like getting HP at half the price, and you get EGT reductions as a free bonus gift.
My first dyno run on a stock truck with an EZ got me 63 hp, 100+ tq, and this was on a cold snowy day at 5k feet elev. (stage one kit). Jim Fulmer got 120hp on his stage two kit.
My only recommendations is that whatever kit you get, make sure you get the stage 2 variable controller. The stage one controller just turns on way too soon for daily driving, works well for WOT pulls, but not 1/2 throttle. Translation - If you are getting this (stage one kit) for racing it works fine, for towing, not a good plan, get the stage two controller. I would also get a couple extra injector nozzles in different sizes. Tuning for individual needs is a bit difficult, but once you get it dialed in... Oo. Oo. Oo.
EDIT - I am not in any way affiliated with Snow Performance, just a very happy customer. I am also not in any way involved with this group purchase, just a testimonial.