I got my propane system for a little over $700. Tanks are cheap too if you know where to look.
I just say propane because yes it is a little bit of an investment but my truck turned over with a tap of the key after I installed it. I was not dealing with a carb that had been sitting for 25 years. (My truck has 26,000 miles...hehehe) The price outweighed my time and the $100 here and $50 here for rebuild kits and miscellaneous parts.
Propane is great, unless you live in California and is a DD. It will never pass the visual for SMOG.
