Guild Wars 2

Is the gem purchase is only available option to upgrade HoT to deluxe? Or there is option to direct pay 25$ for upgrading Basic to Deluxe?

for an upgrade, the gempurchase is the only option.
As the game isn’t out yet, I guess it would be possible to get a refund for basic HoT and then rebuy it for deluxe. But this cost work by support, so pls only do it if it is the only viable option for you.

The CS Team has assisted others that wished to upgrade their accounts. That said, you can use your credit card/paypal to purchase the Gems to upgrade your account through the Gem Store.

Good luck.