But then you dont get data about how much someone is willing to pay. Why not at least have your pricing table and underneath each pricing package, a signup for free call to action button with their own href anchor ( /signup#gold ) to track within google anyltics or something? This way even though people so sign up for free you'll gain a bit of knowledge about which package they clicked on and as a side effect the potential intend. Not perfect but better then no metrics.