Look out for healthcare costs if your partner is not employed.

We don't really want my wife to work when we have kids; however, as a self-employed person, the cost of purchasing you r own health insurance is outrageous. For a family of two adults and two small children, it'll run me over $12,000/yr and that's with a high deductible plan so there will still be out of pocket costs.

Unfortunately, this sole fact is pushing me away from self-employment. That people say the USA is friendly for entrepreneurs is absurd: perhaps if you're well capitalized with other people's money, but not if you're doing traditional self-employment / small business.