dunno what ur deadline is, but if you start hunting now I bet you can find a goodly pile of Olympus Stylus cameras for $5 each at thrift stores, yard sales and the like in short order. They're almost a standard stock item at Deseret Industries in Utah.
Put the word out to your friends, especially at church/work, that you want usable Olympus Stylus and similar cameras for your wedding.
Get a big box to keep them in. A BIG box.