Yep. I totally did. I found dresses I liked at Target for $55, privately asked each of my three BMs what they thought of it, and when they all liked the dress style but didn't like the colour I'd chosen, it came down to me picking the style and them picking the colour.
And I don't feel guilty about it. At all. Every time -- all five times -- I've been a BM, the bride didn't ask what my price range was, she just picked a dress and I was expected to pony up the cash. So I didn't even know I was supposed to ask for a price range. But I still think $55 is totally reasonable. In fact, after dropping more than $200, pre- alterations, on EACH of my BM dresses, I vowed I'd find something pretty, reasonably priced, and re-wearable. And I did.
So what are some etiquette rules you broke that you either didn't know were rules or you knew were rules and didn't care about?