Disk brake cost?Junk yard?

Id save up and buy a kit. After you buy a used disc set up with spindles and upper conrtol arms for around $300 then new upper and lower ball joints,perheps new rotors and calipers and some new brake pads, master cylinder, brake hoses and wheel bearings your gonna be close to the price of a kit if not over it. Id much rather pay the $850 for a new SSBC kit and have it all in front of me then chase down every little part.