Guys, it might be time to skip the bachelor party. A new study by real estate site Zillow and wedding site The Knot says the average millennial male will spend a little more than $1,500 on a single weekend. That number includes travel, hotel and others things.Women spend about $400 less, averaging a little more than $1,100 per person.According to Zillow, if the average person attends nine parties in a lifetime, or three a year for three years, they will have spent up to 34 percent of the cash needed for a down payment on the median home.Bachelor and bachelorette parties are not the only expense associated with attending a wedding.Zillow's study says on average, bridesmaids and groomsmen spend an additional $1,154 for things like wedding day attire, a gift for the bride and groom, as well as travel and accommodations for the wedding day. Guests not in the bridal party still spend $888 on average to attend each wedding.