I could have written your exact post myself, in fact I wondered if I had when I saw the title!
My son is getting married next month & I didn't want a traditional MOB/MOG dress & wanted something on the lines of your dress, which suits the venue.
After trying on a LOT of dresses I settled on Hope & Ivy dress that I loved but I was worried that it wasn't expensive/ special enough.
2 days after I'd bought it, I discovered a family member had bought the exact same dress for the wedding...which had been my fear!
I ended up buying a Joseph Ribkoff dress, which is similar to the Hope & Ivy dress but £££s more, which I'm hoping will make it a little more exclusive.
So, just be aware that someone else MAY have the same dress if you buy High Street.