Cocktail Dresses

[indygphib]

I have been scouring department store sites, Amazon, Zappos, and pretty much every other website under the sun and I am having the WORST time finding a cocktail dress for the BF's 40th birthday party in mid-October. Everything I have seen so far is either too frumpy or too whorish, or it's too casual or too formal. I'm not much of a dress person anyway, and I find it extremely difficult for a thirtysomething like me to find the right style of dress for my age range.

I enjoy looking at the Preference Round dresses on the recruitment threads, but those outfits are geared more for the younger crowd; however, I see that many of you have a great eye for fashion! So who's willing to help a semi-fashionably challenged person like me find a fabulous LBD (or little silver dress) for under 150 bucks? (I should mention that I wear anywhere from a size 10-12, and I have a big butt/large chest so sheath dresses and the like look terrible on me.)