How much do you know about the Mexican marriage? Among other things after the actual ceremony and dancing takes place you have to 'donate' a numeric sum of money to the bride or groom if you want to dance with them. Usually the money in the form of a paper bill is stuck to them or placed under their belt, collar, etc. This is meant as a token or gift of money they will need for their marriage.
I have been to weddings in the US where the men pay $1.00 each to dance with the bride. I think, but I am not positive (it was a long time ago), that women also paid $1.00 to dance with groom. This money was then given to the bridal party. This was back in the '70's when the extra $100 was a lot of money. This sounds like a similar custom.
Yes, the custom sounds very similar to the 'dollar dance' that can be seen in many weddings here in the US. In fact, at my wedding, we did have such a dance. Basically, the bride and groom stand on the dance floor and people line up to dance with each one. They pay $1 to have the opportunity to dance with either the bride or groom. I have never been to a Mexican marriage myself, but would welcome the opportunity to attend one; especially for the food.