Actually, there's "cost" that may be attributed to the taxes depending on the country. For example, Canada has variation in its on-sale taxes depending on the province, but its Tax Exchange agreement flat it out at 15% for any source outside of Canada. The best example is with the Province of Alberta which has a on-sale tax of only 5%. Customers who buy from Alberta will pay a 5% tax on their purchase, but Steam has to obligation of paying 15% to Canada as a withholding tax. Where do you think that the 10% difference will come from?