Well actually I charge extra for a wireless mic. It's not really the norm to have wireless in my area and I didn't get it for free why should they. I also charge extra to MC (not make announcements I mean really MC). That being said it's not normal for the DJ to be the MC throughout dinner and cocktails here in Canada so in my case it's extra prep time involved, extra time the day of, and an extra body to control sound
If that's the norm up in Canada it makes perfect sense. Here in Connecticut you'd get eaten alive charging for things like that. If I were in Canada I'd include MC and wireless mic as a way to get your potential clients