Do you know how many gems exactly and the costs? From asking around, it seems it will cost me about £10 extra than it would normally cost if I upgrade in game -.-
I just said 20$ not euros, however I think it is 2000 gems. Which you don't have to buy with real life money. Other people will buy gems from Anet and sell them in the AH which you can buy for in game gold.
Also pretty sure you can only buy the upgrade in the gem shop. It should be the same price in the difference between standard and deluxe version.
For U.S. standard is 60 deluxe is 80 so we have to pay 20$ to upgrade.