I got my scale off of Amazon as well.. and I started out at around 260. Also have never broken a scale! In fact, like I said, most the ones I've seen say they support up to 300lbs on the packaging. So I really, really think you didn't break it.
My scale apparently is on the heavy side when it comes to weighing people. Boyfriend's sister, mom, and now dad have all told me that it's 10lbs or so over what their scales at home say. Oh well!
Laststraw had a good point about being consistent with when you weigh. I always weigh in the morning, after I use the bathroom, and I am also always nekkid. It's suppose to be the point at which you weigh the lowest from what I've read, and because it doesn't factor in what you've eaten throughout the day it's also suppose to be pretty consistent.
The scale I got is this guy:
http://www.amazon.com/Peachtree-GS-1.../dp/B005LIG10O
It sits on my bathroom floor, cause bathroom isn't carpeted and having a flat, hard surface is important!
Edited to add: Ahahaha, I just saw the reviews. I haven't had any problems with mine thus far, but yeah.. maybe get a different one, lol.
Update again: So assuming my scale does break, which reading the reviews looks highly likely.. I'll probably order this one:
http://www.amazon.com/EatSmart-Preci.../dp/B001KXZ808