I'll tell you why. Shooting your own events tends to put you at a disadvantage creatively, why? because you have your own preconceived notions about each person in the party, so it's either the subject will be too comfortable or too uncomfortable with you pointing a camera in their face. Too comfortable does tend to get a more natural emotions but it can also mean you could spend too much time and effort into shooting one subject, remember there is a lot going on around you and waiting for that moment when the light hits Jenny's eyes just right is just too much effort (for an event especially if you are shooting alone) and might cause you to miss an important event. Too uncomfortable and there's probably going to be a hand or some obstacle covering your subject's face. To add if you are a guest or the host of the party you will never truly be able to join in the fun and festivities and you will most likely (except for the odd snap by cousin Larry) never be the subject on the photos.
My point is a pro is removed from personal feelings you might have of your guests or fellow guests, so the pro is more objective and also knows from experience where to position him/herself and knows what to prioritize.Speaking of which having and knowing priorities is very important in an event photographer. Do you position yourself upfront or at the back during the exchange of vows, close up or wide angle, flash or ambient, shallow DOF or more DOF, shoot in burst or single, what ISO to use, what WB to use, when and what lens to use? I apologize for the jargon, the point is the photographer is making dozens of choices in each shot and those choices make or break a photograph's appeal. While to most people it might not make a difference, it does to the photographer. As a photographer you should be your own greatest critic, never be satisfied always strive for that perfect shot.
Here in the Philippines it is not unusual to find a resident photographer hunter or hunters in every church. And before things get out of hand Photographer hunters are not people predisposed into hunting or killing photographers, 'hunters' are the term used for photographers who stalk a church or venue waiting for a wedding or event to take place, and shoot that event with the intent to sell prints at an inflated cost to their respective subjects just minutes later. From my experience these hunters still are able to earn a pretty decent living with these tactics, which means that, for us Filipinos there are still those that value a true hard copy of photos. The emergence of Photo booths have cut deep into these 'hunters', why pay if you can have a printed photo for free. While they are also considered pros they also have no obligation to you to produce and thereby quality can be sacrificed for quantity in this case. I am not saying that 'hunters' are no good its just that if they can sell mediocre looking photos with as little effort as possible, they will because it doesn't matter, tomorrow (or maybe even later) they'll be off shooting some other event and your event wouldn't have mattered that much.
Hired pro photographers, try to get to know you and at least try to devise a gameplan on how to shoot your event. Trust me when I say that pro photographers treat each event uniquely, no two events are ever the same (duh) The significance is that the pro is always on the lookout for something new, something fresh, a new idea, a new concept is born every second. That plus the pro knows what is expected of him/her, so you get what you expect and then some. Most pros also package their services with an album or prints, something that a casual snapper will most likely not be able to produce. Let's face it about 80-95% of the photographs you've probably taken have gone straight to social media sites or emails. I have a classmate, knows pretty much all that I know, she got married 7 years ago, got friends to take their wedding photos and until now no hard copies. Come to think of it I haven't even seen the soft copies. Pros on the other hand deliver, because they have to. So my point is, you should hire a pro for your next event. I'm pretty sure you'll thank me for it.
At the moment there are a lot of premium and well established photographers that could charge you an arm and a leg, but there are also some cost effective solutions (in other words cheap). You can check out BUD Photo, the latest photo and video service provider which offers affordable packages for Birthdays, Debut, Weddings, Anniversaries etc... you may visit their website http://budphoto.weebly.com or contact 0927-3440923/348-4291 email firstname.lastname@example.org