Actually, I meant expensive, but I did say relatively. In the grand scheme of things it may not matter to you, but it may. Keep in mind that almost all of this varies from state to state, and again IANAL, but in my state, I believe a sole propretership is free, or just the cost of a business license. An LP is $100, and an LLC is a minimum of $300 (it can go up to $3,000!). I'd say three times the price is "relatively expensive," and an LP may suit your needs. One or both of those could be annual costs too. I honestly don't know the costs of corporations, but my point is that LLCs are not the cheapest option out there, even if it's not enough money to make you flinch.
dmp