Have the currency but still can't buy from npc

[Hollowborne]

This may seem terribly noob and obvious but I don't see it.  I have 702 currency.  I want to buy camp supplies from the blacksmith in the Vale for 150.  The camp supplies appear on the lower left of the store screen with the 150 amount below it with an arrow pointing left.  I click the TRADE button and i heard the sound of coins dropping but I neither get the camp supplies nor do I lose any money.  What gives?

[LadyCrimson]

You may already have the max camp supplies for your difficulty settings, so the game isn't allowing you to buy more.

 

Easy=6

Normal=4

Hard=2