I have a ZEX kit & love it. I really wouldn't worry about the cost of filling your bottle over & over, I've used my kit the whole summer & only filled it twice, both at less than 40 bux a pop. If you get a 10lb bottle (standard ZEX size) it should only cost 3-4 bux/pound. also, unlike some of these jackasses that feel the need to have their bottle on while driving on the street ALL THE TIME, i only turn it on for days at the track & the occasional test down a backroad. ZEX rules, but i think I might convert over to their wet kit, i've ran a 65 dry shot w/o problems all summer on my lude w/ 170k miles, though. I'd take the precaution of upgrading to an aftermarket high flow fuel pump. I got my walbro pump for 90 bux, and never worry about running my motor lean.