The Kilby set up is actually very affordable if you dont mind doing some searching for some used parts. He sells the mounting kit with idler pulley and both new belts for about 150. 00. If you want to search for a used compressor and clutch, you could do the whole thing for way less than 500. 00 I bought everything new and had about 700. oo in it. The thing for me was performance. I have not seen a single 12volt system that performs near as well as my engine driven system. As far as oil consumtion, i dont really notice any. I have the coalescing (sp?) filter on my system with the kilby return line kit and all i do is return a little oil every couple of weeks if i have been using the system. I run a 1/2 inch impact on mine and have no problems with enough air. If you were blasting it for a long time you might, but i never have run out with an impact. An air grinder uses it up pretty quick, and you can only do short blasts. But I only have a 2. 75 gal tank.