Indeed a good idea to consider tax payments as that is significant in some locations. In Dubai for example there is basically a 20% tax and now a 30 AED a night (8 USD) charge per night. At the Grosvenor House where I was going to stay this added up to roughly $65 a night! I don't know if the 30 AED a night is added to points stays... I think it will be as it is a government fee per room for some reason, not sure why.