It really is all about that phone call. Let's take price out of it for a minute, because you don't want to compete on price anyway. So that excepted, brides select their photographer based on two things; a style of photography that appeals to them and a feeling of connection with the personality of their photographer.
When someone sends me a note through my site, I already know my work appeals to them. So that phone call becomes all about making a connection. If the call ends with setting up a face to face, I know they're already sold. (BTW, I post my prices on my site).
Get them on the phone, ask them about the day they're planning, gather thoughts they already have about photography for their wedding, talk about what makes your approach unique, especially focus on how you will manage your interactions with them throughout the day. I have had SOOO many brides, probably more than half, who say that other photographers they've spoken with never really asked about them or what they want at all. Get them on the phone and build that personal connection.