Man, what's with the people questioning his motivation? If he wants to weigh his bikes, that's his prerogative. If it wasn't for people wanting lighter bikes, we'd all be riding 40lb monsters, and even the "steel is real" crowd doesn't spend that much time on Schwinn Varsities these days.

That $8 scale should be fine.

If you're going to be flipping bikes though, it might be cool to spend a little extra and get a "legal for trade" scale, but that might be out of your budget.