I agree, and I'd link that to why nobody is paying attention to the "usefulness guarantee". You really need to think about who you are selling to. For a corporate client the time and expense and the risk of dealing with you will equal or exceed the $450. Think about the project manager that is going to have to order your service: $450 is not a lot but they are going to have to explain it to others and it's going to look embarrassing if you turn out to be just some random dude on the internet who takes their money and then sends them a bunch of 'duh' statements about their web site. They have a very CYA mentality, which like it or not you have to deal with.
To get started perhaps you could think about a 'first taste is free' model where you do a review of part of their site (say, 1 page) with no obligation and then based on that they can go to their manager and justify the expense.