I honestly do not see any equivalence - a kind gesture is a kind gesture, and one says thank you (if you have any sort of manners). a dinner invitation isn't more important picking up someone's favourite candies or a nice sweater, just the money/effort involved may differ. and a gifter's intent should never be to score something in return.

frankly, some guests at dinner may not be able to return the favour; if someone isn't equipped/monetarily or physically able to host in return, does that mean they have to stay home perpetually?