How do we find someone to just prepare the food for an event?

We are having a 50th anniversary party for my grandparents and there will be about 50 people there. We would like higher end food, but ofcourse that is pricey. A friend of mine works at a food distributor and can get us whole Maine lobster and a whole prime rib for a price that is just unbeatable. I just do not know about how to go and find someone to prepare it. Any caterer would still be way too expensive. About 5 of us grandkids are splitting the cost for the party in whole...so please no nasty comments about being cheap. This is their present for their anniverssary. Between the food, alcohol and decorations, party rentals and such we are already over what my wedding cost...so we are not being cheap, just trying to find a deal. Thanks for any help.