Upgrades within versions (e.g. from 2.5 to 2.6) are free for our customers. When we release a new version (e.g. from 2.6 to 3.0) existing customers can always upgrade at a discount.
As for support: we've got a great world wide support team manning the forums. Usually, questions asked here are answered within 12 hours on work days, and 24 hours during weekends.
