Think of it as a Turbo Installment plan

Well lets be pretty straight forward, a GSX in good condition may cost 4-6 thousand more than a Non turbo 420a. The cool thing about buying the cheaper car and upgrading it is its affordable. Most kids can only afford things 200 dollars at a time. Which rules out buying a GSX on payments becuase its very likely noone will finance you. However you could buy a turbo for 200, then a turbo manifold for 200 then a tial wastegate for 200 then a FMU for 200 then a Intercooler for 200, and even intercooler piping for 200. The point is for most people its much easier to dump 200 per paycheck for 8-10 weeks and had a turbo system that can run 5 psi boost and be around 200-210hp.
It can be done, I did it a couple months ago and I purchased all fuel equipment from Hahn ( since they have turbcharged so many 420a cars I wanted it to be right) It costs around 1000 in parts to upgrade your fuel pump, fuel hoses ( to stainless), FMU and bigger injecters. Hahn is pretty good and Star doesnt exist anymore but the setup was simple and easy to replicate. I combined the tubonetics turbo, star manifold and hahn fuel system. If you are looking for even a little more performance dont be a wuss. Turbocharging is the best bang for your buck even if you only want a extra 40 hp you will thank me. You can do it and theres many of us to help you! My install for the 420a is here http://upgradecar.blogspot.com/2007/12/starnes-420a-turbo-install.html

All the costs that I incurred I listed to the right side. Dont be scared only 2/3 are cost you actually need to spend, I go above and beyond whats absolutly needed.