wedding reception food?!
Basically, the less meat, the cheaper it will be. But then you have to fill in with more carbs to fill people up.
I went to a wedding once which had all appetizers instead of a big meal. It was fun and still filling. Later, the bride told me it cost them a lot less to do it this way. Pasta is also cheap, but it is hard to serve it to many people because then it sits and becomes sticky. Soups and salads are good, lots of bread.
How many guests? Are you doing all the cooking and prep and storage of food? I'm assuming you're thinking of buffet style. Are you wanting to know what's best to order with a caterer? Also, how much do you want on the menu? Need more info please.