Flowers

I don't live in NY so I'm trying to do some advance research on how much flowers will cost for my November wedding. I really like the look of having several long stem flowers tied with a ribbon instead of bo-ks. i'd need:
1 of those for bride (bigger)
6 for bridesmaids (smaller)
about 7 bouts
3 corsages
about 15 low centerpieces

i'm interested in calla lilies and roses mainly. any ballpark estimates would be great!