What look are you striving for? You could do a great macabre look for a wedding on a low budget. Some simple ideas would be large tree branches spray painted black placed in urns throughout the room, ornate tarnished silver platters for serving food (can be bought at rummage sales), foggers and lighting of course can all be rented at almost anywhere. Perhaps light the room in a hue of blue tones and use a bunch of various sized pillar candles grouped together on platters as your centerpieces. Just a few simple ideas, would be glad to help out with more.