I like the fact that everything is in front of you as you're going through the custom choices, very easy to use. The only thing I might suggest, would be to dress up/clean up the right hand side "Your Custom Axioms" by keeping the cost of the options to the right; I don't know about other people, but I like to clearly see the effects($) of my itchy mouse finger and the other thing would be to either space out each heading on the right side "In a...", "With Custom...", "Your Finish..." ect or add an alternating bar of subtle colour so it's easier to see all your selections under the different headings.

I hope that may be some constructive help, Ian. I like it though, it's user friendly.

Half of communication is listening. You can't listen with your mouth.