I discovered Danielle's Consignment a couple of years ago and rarely go anywhere else for my consignment shopping. The store is small with little wiggle room. It is touch and go whether or not they will have two or three change rooms available (they sometimes use one change room as storage for newly consigned items). Consequently, the wait times for a change room can be lengthy - make sure you exhaust the number of items you can try on on a busy day so you don't have to stand in line twice. Otherwise, I find their selection really good if you have the patience to take the time to look.
I recommend you sign up for their newsletter to receive noticed of their sales - they have 50-75% sales seasonally. Otherwise, I would agree that items can be very pricey for consignment clothing, even the designer pieces.
I've never consigned there so I can't speak to that angle of their service.
Cheap parking on weekends makes this an easy trip but go earlier on Saturdays and Sundays to avoid the rush.
In short, leave yourself enough time, be prepared to feel claustrophobic, and you'll find your gems!