My FI's parents are willing to pay a lot for our wedding because they want to have 300-400 people. My FI keeps saying that it's not a big deal, that we'll get a lot of the money back in gifts (checks). First of all, I don't think we can/should expect to get the money back, as not everyone gives monetary gifts, and people don't always cover the full cost of their plate (plus other wedding costs).
Second of all, is it appropriate to give some or all of that money back to his parents if they are the ones laying out a ton of money for the wedding?