@thebloodycoon - if you purchased less than one year ago, login and go to My orders and you'll find a download link which always pulls the latest package. If it's been over a year, you need to purchase a new license. Once you have the updated package, upgrade instructions are inside.
@jcmyers - You've always been able to have modified pricing based on the size of a group. You can have that and also use field selections to modify pricing for the overall group and/or each member of a group. Regardless, you definitely should update also.