Here's my experience working with and hiring photographers...you get what you pay for. This is one category where you need to really think about what you want out of your photos and then hire the best photographer that your money can buy.
But man, that seems like a lot of money! I hear so many couples talking about their photography budget and how much they actually spent and how it was way more than what they expected. But, think about it - this is one vendor/professional who is with you most of your wedding day, if not all of it. Depending on which package you book they are potentially there when your getting ready, when your on your way to the ceremony, when your tearing up thinking about walking down he aisle to your life pattern. You depend on them to capture emotion, love, movement and laughter all in one shot. And, let me just be honest, that is a lot of work, patience and effort. This is one vendor/professional who barely eats during your wedding let alone take a bathroom break - they don't want to miss any magical moment you may have while they are gone.
So, when considering photographers I suggest you look at their portfolios decide on a style you like, maybe you like natural non posed photos and would like a more photojournalist approach or perhaps your a romantic at heart and want whimsy and soft lighting or maybe a more modern take on tradition is what you strive for. Look at a lot of photographers portfolios decide which style you like and then interview them - I mean if your going to spend all day with them you may want to make sure your personalities gel.
Lastly, it is a lot of money, but remember after all is said and done your left with a marriage license, each other and hopefully if you chose well and spent well amazing photographs!
Check out my venues and pros page for some suggestions of professional photographers that I have worked with and love.