ah, that probably accounts for the discrepancy. I think the in-state figures may be more relevant to the discussion at hand though. why would someone paying their own way through school choose to forgo the in-state discount?
Strength of the state universities in a desired field. Some state universities offer much better quality and reputation of their programs than the ones in other states. The way that college is marketed as a social vehicle is that you choose the best one that you can get into, and it's worth paying for because of the connections and job opportunities you'll get there. (Scam! Holding people hostage for runaway credentialism!)
For instance, several state universities are listed as top-tier mechanical and aerospace engineering schools (consider Purdue vs. Mizzou aerospace engineering), so if you want to seriously compete in the field, it could be worth your money to join the "better" school from out-of-state, assuming you're a competitive student. The recruiting, research, and internship opportunities at top state schools are way better than at low/mid state schools.
However, from a pragmatic standpoint, you are correct- it is unwise to select these schools if you can better afford the in-state discount. You just have to deal with the limitation of your selection of available fields and prestige of chosen degree. (That's why I think it's a scam; as any honest manager will tell you, degree/curriculum content means very little relative to job performance; the top performers come from top schools not because the top schools made them top performers, but because they were already top performers in high school and just got chosen by top schools.)
It's worth mentioning that if you pay out-of-state tuition to attend a highly ranked State school, you are almost certainly not going to become a median earner. You will comfortably find yourself spending most of your career in the top 2 quintiles, if not the top quintile altogether (~$100,000 salary puts you in the top quintile).
If you're below median and would like to attend, you're going to receive FAFSA, Pell Grants, on top of university-specific discriminatory pricing that favors the poor.
There's no reason one should pay out-of-state tuition outside their own State unless it's at a "top-tier engineering school", in which case the point is basically moot.
