conversation: User (SAHD31): "I'm looking to get a 529 plan started for my kids (ages 4 and 1). I live in ND and my wife makes 325k a year. I researched plans and our state's plan doesn't not rank as highly as others (AK, UT, etc). We would get a state tax deduction of up to 10k a year by using the ND plan however. Would that deduction outweigh the potentially higher returns in a better plan? Thanks for any advice you guys can give me!"
  Self: "What tax bracket are you in? If your marginal state income tax rate is 3%, for instance, the 10k deduction is worth about $300 to you (less actually, because that's $300 you're no longer deducting from your federal taxes, which means you're really only going to see about $200 of that in your pocket). Depending on what you mean by "better returns," it's almost certainly the case that investing outside of your state plan is the way to go."
  User (SAHD31): "The few articles I read on the various plans showed a higher earning potential in a handful of states. I'll have to hit the calculated and find out what our state income tax is projected to be and see if it's worth it. I'm assuming the total state tax will be fairly high though due to her income"
  