http://www.scrapmetalforum.com/showt...76-Cheap-Scale
This ones for weighing buckets, or this guy has a large variety of different scales.
http://www.oldwillknottscales.com/
We got a 75 pounder with a remote head that you can take off for large boxes. It cost us $33-35 and has been well worth it. We weighed up our buckets of copper and alum. we just took in and the yard scale gave us exactly what we saw on our scale, that way no surprises. Kinda like this one, not it specifically.
http://www.amazon.com/UltraShip-55-D.../dp/B000FSWB9K