I've personally filmed over 50 plus weddings, and from the mouths of many bridesmaids I talk to while I'm there, they all tell me the same thing; "I WISH I HAD A VIDEOGRAPHER AT MY WEDDING".
I won't downplay the importance of wedding photography at all, heck I am a wedding photographer myself! But really, if a picture is worth a thousand words, imagine how much a video is worth!
This is something I try to explain to all my couples when I do engagement photo sessions. And that is, in 50 years when your memory fades, a wedding video will absolutely bring back to life the memories of uncle Bob getting a little tipsy immediately following the ceremony. Or Patty, your high school bestie showing up after not seeing her for a few years and remembering the scent of her perfume when you see yourself hugging her in the video.
So the importance of a videographer is absolutely something to think about and expect for a wedding day.
That having been said, after reading various articles on the cost for a videographer, it is averaging around $2500 or so.