I'd recommend you stay away form "photocopy shops" entirely. Both the quality and price is terrible compared to these small pro places. Look for places that pros like architects use. I used to copy plans on Kinko's large format scanner/printer. Never again.

BTW, I sure wish there were someplace reasonable like this in Japan (or my part of Japan). It would cost me a royal fortune to have large format plans made here. So I get all my plans done when I'm in the US and almost always come back with at least one mailing tube.