Skill books are always my priority. DOS is very much a game about piling on status effects and elemental damage.
The thing to remember about the economy is this is still very early in the game. I remember having the same problem in DOS 1 at the start but by the mid point (level 11) I was drowning in gold with seemingly nothing worth spending it on until I got to the end game merchants.
Slightly unrelated, but jeez, I wish you could swap items between characters on the trade screen
I could see that being exploitable and prone to duplication bugs. But I do wish all transactions in the trade screen were done with the barter/charisma stats of the character who initiated trade.