Junkyard mufflers

I need a couple mufflers ultracheap. Thinking about going tomorrow morning with my Sawzall and checking some of the trucks and older Vans to see if anybody had some cool dual exhaust. I was wondering if anybody had any luck with something like this before? Thank you..
why do that? just go to Autozone/Advance, get them for 20 bucks. You'll pay close to that for used junk at a yard