I heard Costco has decent flowers. I used them for my colelge graduation last year and they were good.
Flora Fresh is a wholesale florist, and Im getting all my flowers there, but you do have to have a sellers permit. I just borrowed my boss' permit, and put my name and hers on the account. Im saving SO much money. I did a run through myself, and it was actually really fun to put it all together. Good luck!