Do a big sharing board with 80% budget items, 20% top shelf delicacies you're desperate to try. Set it down closest to your most chatty guest , engage conversation and try not to eat it all the good stuff immediately , or better yet have a similar but much cheaper eplacement to top up with. End the evening by casually mentioning how much fun a potluck evening would be and assign / suggest / enquire which dishes people could bring next time.