Unless you plan on keeping your bouquet on display in your home, don't bother with a duplicate to toss.
Instead of tossing your whole bouquet, just pick one flower to throw. We all know what condition the bride's bouquet is in after 30 women (or more) start clawing at it.
Silk flowers save you a lot of money and they're already preserved. The Bride can have fresh flowers, but there really isn't any need for everyone else to go fresh.
If you're using flowers in your centrepieces, decorations or large altar arrangements, go with silk. Would be nice if your guests could actually use the centrepieces that they just won again. You could re-use the decorations and larger arrangements at home, party accents or resell them.