Cake&Punch AND a registry?

So me and my fiance are figuring that we probably cannot afford a big reception (as in at an actual venue with catering/DJ/open bars/etc). We both work part time jobs and already have bills to pay as it is. However we do want some sort of "reception" after the ceremony to get together with everyone. We are planning on setting up a registry at bed bath and beyond to help us get started for once we've tied the knot. However, we might only be able to afford a "cake and punch" reception in the basement of our church (where we are having the ceremony). We will probably be able to get more than strictly cake and punch (maybe a few more light snack options and obviously a few more drink options than punch). However is it tacky or rude to set up a registry and only offer such a small reception? (We would include on the invite "cake and punch reception to follow" so guests know what's happening.) We can't afford a few thousand dollars that a venue will cost us, plus all the added extras. HELP!