You cannot compare the two really ...
- The USA has a uniform federal tax code. The EU tax rates are regulated by the nation-state member.
- Labor rates might vary 20% in the USA but the labor rates in Western Europe and Eastern Europe might vary 65%.
- The effective tax rates are lower in the USA for business.
- Comparing the costs of doing business in London as opposed to New York City might be comparable. There are no comparable American cities to Prauge, Budapest, Bucharest or Sofia.
- EU privacy laws and social attitudes toward most adult enterprises are better than the situation in the USA.
- Taxation, VAT in particular, is a negative in the EU -- your product's price is less competitive in many global markets.