Just because you are on a budget, doesn't mean you have to give up on having a completely awesome theme for your wedding. For a mid-afternoon wedding consider a candy buffet. Mmmmm....candy! Set up a bar with all your favorites and choose the candy that fits your color scheme and personality. All you need are clear glass jars and a trip to your local candy stores and you'll have a plethora of choices, colors, tastes and varieties that will have your guests on a sugar rush in no time at all.
If your wedding is in the fall, consider caramel covered apples, candy corn and sweets in shades of orange and yellow. If you are planning a winter wedding, pick up candy canes, cinnamon sticks, and red and white candies. If your wedding is in the spring, take advantage of the pastel candies that come out around Easter. And if you are planning a summer shindig, add a sno-cone bar with flavored ice as a special treat that is as tasty as it is thirst quenching.
Above all, be creative and be sure to brush your teeth after such an indulgence. Sweet dreams.