I have done some group orders from reeftopia before, and was actually thinking about placing another order from them soon. I've been really happy with their clean up crews, we usually buy bulk nassarius, cerith, astrea snails and hermits, emeralds, and peppermints. pm me if interested, I'd be doing it either late next week or early the following week.
Although its a good idea to also check with Chris, his prices are generally great too and I will order through him if nobody is interested in a group order.