State income tax for each state for full time employee?

joshbegin wrote:
but the company has stated that the tax implications (to them) are too high to justify having an employee there.

This sounds to me like a SALE TAX issue not an income tax issue. By having a employee (Office ? -- present?) in a state, the company may need to collect sales taxes on all products sold in that state. Many states have different sales rates for each city or county in the state. The Sales Tax issue (cost to collect) is much more of an expense for a company that the income tax issue.