Buying online is over rated, I tried.
Heres my thoughts, by the time you've bought either $200 of corals (for the free shipping) or added $40 - $50 for overnight shipping you'd have been better off buying locally at a frag swap, members here or a LFS.
Take a road trip, G at ABC aquariums has a sale right now, Cardiffgiant has zoas and SPS from $5 listed here, CF is always good in Rochester ....... heck I could make a Syracuse to Buffalo and back trip in my truck and still use less gas than overnight shipping options.
If you're just looking for a lot of corals to fill your tank and are not too bothered by buying named stuff, take a look at Atlantic Sea Farms, they offer frag packs at reasonable prices.