Look closely online. I found a 50 Qt for 35, there was another member who found a 60 Qt for 45.oo bucks to. The best recomendation is patience and diligence. It will pay huge dividends fairly quickly. I too am building and all grain sculpture and system and have managed to keep the cost way inder the 1800 dollar price tag of the commercial basic 10 gallon set up. So far I am around 1/4 or less and will have a HT, 2 Mash tuns, and a 60 qt BK. It all goes in a beveridge elements kegging system for force carbing. All together with kegging, microscope, hemocytometer, all the kettles, a burner and the iron to build the sculpture I am in for about 350.00 or so. I have to get the CO2 cylinder filled and maybe one or two minor items, but for the most part I am done buying and need to get busy assembling. I also have a corona mill and a stir plate so I can grind grain and grow yeast. My hops will eventually come from my "backyard hopyard". So attention to detail and patience does pay handsomely. An ALL of this is to brew my SECOND batch ever....
Bob