Does being incorporated cost more in taxes?

Does being incorporated cost more in taxes?
The answer is 'it depends.' If the corporation was established in one of the few states that has no corporate income tax, the answer is most likely 'no.' Even if your business is internet commerce, the US Supreme Court has ruled that states can not force you to pay their sales tax on sales into their state.
If on the other hand you incorporate in a state with corporate income taxes, you will have to file a corporate income tax return and may or may not pay corporate taxes.