This centrepiece is very cheap because it can be realized with flowers and fruits of your garden.
You can insert a sponge for flower compositions into a little container. Pour some water over it and let it get wet for about some minutes.
Now you can begin arranging some leaves of hydrangea, some colorful flowers of "zinnia" and two or three little peaches. The peaches must be stuck into a little skewer.
You should arrange all the leaves in order to hide the little container.
Naturally this is a suggestion; if you have other leaves or flowers or fruits, you can use them following the same instructions.