If you don't have 2 Wizard Schools, I would buy those as a priority.
I think the Fortune Teller is a waste of money, I never got anything from it that I needed.
The Barracks is good and you will be able to send out on 3.5 adventures per week, getting gems/energy back but you need to keep it in supply with Feasts to do so.
If you don't have a dragon, then a Mithril Dragon is a good buy,