There are a couple things to keep in mind when buying the flowers.. choice of flower, time of year, real or fake. If you know what season you're thinking of, try to pick flowers from that season, and you'll save some money, whether you're going real or fake. If you're opting for fake flowers, buy them at the end of the season when they go on clearance. I spent about $50 for my two bride's maids bouquets, aisle flowers, toss bouquet and leaves (we're having a fall wedding) My Mom spent just over $100 for all the ones for the centerpieces, baskets, my bouquets, her corsage and the boutonnieres.
It also depends on where you want the flowers too. If you're not going to use them for centerpieces, then you'll save even more.