Only serving cupcakes for my reception?

Hello! I'm just hopping on here because I am so torn on whether or not it's okay to just serve cupcakes at my wedding reception! My fiancé and I are broke college students working to save enough money for our wedding, and although I really wanted an evening wedding, we decided against it because of the fact that we wouldn't have enough money to serve a full blown dinner. So now our current time slot at the venue is 9am-1pm (we can start or finish whatever time inside that slot). On top of that, the venue doesn't allow outside *any* catering or outside food other than cake/cupcakes (which means absolutely no other snack foods/veggie trays, etc), and their quote for just hors d'oeuvre was a little over $4k, which absolutely blows our budget out of the water. I'm wondering if, 1. just serving cake/cupcakes would be unacceptable and rude, and 2. how to make sure everyone knows, so they won't be expecting anything other than just cupcakes. I've debated putting "cake and punch reception", but I know that some people will still think there would be *some* other foods. I know this isn't ideal, and I would love to be able to feed my guests appropriately, but unfortunately this is our current situation.