Can you buy Wood, Stones, and Hemp?

Yes you can. They are sold by bulk at a very cheap price in Hope 101’s grocery and Nine-Dragon’s restaurant/ steakhouse. You can buy 400 Wood or 100 Stones for 100 new dollars. You can buy up to 10 times per day. This limit will be removed as part of the game’s daily reset.

If you're a member of a private camp, look for the merchant from the Trade Federation Commerce Bureau in your camp's town hall. The prices are the same as what are sold in Hope 101.

With the introduction of the Manor Vault system in the July 4 update, you can now exchange Security Points to get bulks of wood, stones, and hemp. You can do this by accessing your Manor Controller > Vault > Exchange Tab.

You may be wondering, why do you need to buy these two basic resources when you can just farm them?

Well, the answer to that is convenience. Later on, as you grow stronger, you’ll want to shift your focus on doing other things like completing missions and farming for secondary resources instead. Basic resources like Wood and Stones tend to be used a lot, especially when crafting individual components needed for much bigger / better items. If you’ll save Vigor and time by buying them instead of manually farming and shipping them, then by all means, go for it.