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These are both good ideas. A "tax free" amount would be nice. But 10-50 is nothing for even a moderately sized guildhouse or temple. It should be based on the size of the temple. For a level 5, I would say 100-200 is a reasonable sum to have tax-free.The change to tax on income is also a very good idea. It preserves the ability of religions to stockpile cash, while limits the banking. I believe it should still be at a tax-preferred rate (maybe half or a quarter of the local rate), but it should happen. You could process it either during the transaction or weekly, I don't know which would be easier. But this is an excellent idea.