You don't have to pay large "per hour" fees in the initial design phase.
There is alot of "Trial & Error" in designing your perfect website. You may go through several versions before you settle on the right look for your site. By charging "per page" I allow you to make as many changes as you like while working on the original template. You don't have to feel that you have to "settle" on a design in order to minimise costly "per hour" charges.