The granular feature selection is nice, but I am selecting features - and being charged - before I know enough about what they do to make a decision. As has been stated elsewhere, examples/ a showcase would go a long way to ameliorating this issue.
Felt like you were trying to make a transaction happen before you had sold the product - I was choosing features and being shown costs before I had any idea about how they would work or how I would go about constructing them within your system.