you can get the vases at Dollar Tree, 3 bags of rocks and the floating candles in a 6 pack at Hob Lob. With a super gorgeous orchid as the flower, in the colors of the wedding, you've got yourself a very pretty, and very thrifty centerpiece!
Ideas for non-floral centerpieces : wedding Fish.I'm not sure how are the candles are for the fishes though. Maybe separate candle area. Green and blue fish -- guests can take home? What if we end up with all the fish though.