Guild House is pretty, quite expensive and... mostly useless. So, a little tweak suggestion: give it a production cycle.
Cycle: 18:00 minutes (+ walking etc)
Consumes:
- 1 iron bar
- 1 gold bar
Produces:
- 2 guild coins
No buffing allowed. This would produce up to 156 guild coins per day at a cost of 78 iron bars and 78 gold bars. Considering market price for those goods, it would be profitable, but not excessively so. A little something back for paying the construction cost of the building in the first place. Alternatively it could use titanium/gold bar combo, but then it would have to create 3 coins already (adjust cycle length longer accordingly).