[RICE RACING]

Water Injection properly applied is NEVER cheap.
If co$t is a variable that defines your choices then up grading your heat exchanger is the easiest path. Given what you are doing and planning an upgraded intercooler is the way.

I suggest you do the following.

Box that intercooler, turn it into a water to air set up. Buy a cheap ass water pump and control, and a small front mounted heat exchanger and some hoses, this will solve ALL of you temperature problems and cover you to triple the power you use now. It is one of the best options available which most people discount, I have done it many times with great results.