Looking for a easy, cheaper hive scale. Has anyone tried something like this?

http://www.amazon.com/gp/product/B006CJ34CO
http://www.amazon.com/Pelouze-Mechan.../dp/B0017GLYII

$90 receiving scale. They seem to be pretty rugged / rustproof, and fully mechanical. The slanted window looks like it will be visible even under a hive. Unfortunately, both of these top out at 250 pounds. Do you think it would work out?