Help with dress search needed on a budget!

Hey All, first Reddit post here but an extremely important one!

I’m in need of some serious help here with dress shopping. I love boho style dresses (specifically from Lovers & Dreamers) but I’m trying to stay under $750 for the dress.

Are there any second hand sellers where I can look at the measurements of the dress before buying in my price range? Any online stores you’d recommend? I’ve tried Lulus, Anthropologie and local stores.