I think parisbella.com's dresses are fabulous and very reasonably priced. Granted, I've only seen one in real life but it looked very unusual and very expensive!
I'd recommend looking in their "evening dresses" section rather than "bridesmaids dresses". Here are a few examples of ones I think are nice (though obviously, I don't know what you're looking for). Some of them come in a few different colours too!
I've spotted one on there that I love. Do you know anybody who has ordered from there?