Feldon 
One of the most popular questions about EverQuest II’s twelfth expansion Terrors of Thalumbra, which became available for Pre-order and Beta Testing last month, is whether players would later be able to pay the upgrade price to jump from the Basic ($34.99) to the Collector ($89.99) or Mack Daddy Premium ($139.99) editions. Players also noticed that the expansion could not be gifted during the Pre-order/Beta window.
EQ2 Lead Designer Kyle “Kander” Vallee has provided us with answers to both of these issues!
You’ll be able to purchase an upgrade to any of the sets on launch day. Gifting should also be activated.
Why did my brain read that as “grifting”?
I may need a break.
Why on earth did it take so long to pipe up and answer this?
Because scarcity and conveying the feeling you may miss out is a standard marketing practice. They would have likely seen a huge reduction in collection/premium pre-orders if they included upgrading as an option in their original communications.