The front page of a recent Chronicle of Higher Education held two headlines:
These two stories, one of student loan debt and one of student migration are very much related. According to the College Board, the average public four-year college charge this year (after deducting financial aid packages) was $8,244 in tuition and fees for in-state students. Out-of-state students paid $12,526.
This is just for illustrative purposes, because financial aid can vary so much, but that's a difference of $17,128 over four years. Add in the increase in travel costs (air travel at Christmas, for example) and you might round up to $20,000.
Public universities recruit from out-of-state for a variety of reasons. A larger pool of applicants helps a university attract diverse and high-quality students, which changes the academic climate and helps with rankings and reputation.
Out-of-state students also pay the bills. In some cases, they pay as much as private school students. In general, they help states meet the university's financial needs as state governments slash funding.
Is it worth it? Maybe. It's a question of priorities and goals. Does the school a few states away have something you can't get at home? Do you dream of being a marine biologist but live in land-locked Idaho? Does the company you dream of only hire engineers from Purdue University? In other words, does a certain program increase your chance of success?
If the answer is "I want to be an English major" or "I think I want to be a social worker" then check out what the nearest state school has to offer and save yourself $20,000.