Guild Wars 2

Is there a way to pay for the 49.99 pack then upgrade to 99.99 pack later?

Can you pay for the packs with gems from the gem store?
-> If so, then which packs can you pay for in the gem store?

Can not upgrade to ultimate if you buy standard or deluxe. Can up grade to deluxe from standard in gem store. Have to buy Ultimate from start to get it.

Can not buy expansion with gem. Only thing with gem can buy is upgrade from standard to deluxe after buy standard with money.

Okay thanks for the answer