Crafting in GW2 is the least relevant i've ever seen in an MMO. It has no bearing until max level, where its use is still questionable. There are much cheaper sources for the gear crafting can provide, and its only use is for crafting niche items that go into the forge -- or collections, if thats your thibg. The Expansions are level 80 content and since it is better to level one or two characters to the max level anyway, you still have a lot of time until you would need either expansion. You could also just play the core game and then Season 2 of the living world until you start with HoT. puZF.