Since I am paying for the wedding myself (FI bought the house) we were planning on having a cash bar (extremely common around here.. etiquette or not) and only hosting wine at dinner.
He suddenly decided he was not ok with a cash bar and wanted to contribute. I don't think he really realized what it would cost though ($2.50/person + consumption ($4/drink) + $4.00/juice container + .30cents/wine glass + $100 collection fee or something). While he likely would still pay it, he already gave us a large sum of money for a Christmas present (new flooring YAHH!).
We don't want him paying too much so compromised and are now having a toonie bar. Makes me feel better about having my guests pay for drinks when they are only $2.