OOS tuition at public universities is typically high. However, some public universities will discount the normal OOS tuition to residents of neighboring states. In effect, such discounts represent large grants to OOS residents.
For example, the WUE program allows public universities in western states to discount the normal OOS tuition for residents of other western states. In general, the best-known public universities in the west (e.g. most UCs, UW, CU) don’t participate in the WUE program – they have no incentive to discount, since they get plenty of OOS applicants who are willing to pay full price. But many other respectable state universities do (e.g. UC Merced, Nevada-Reno, Colorado State, Washington State).
http://wue.wiche.edu/search_results.jsp?searchType=all
WUE is only for residents of western states, but there are comparable programs in some other parts of the US. Since you haven’t indicated your state of residence, it’s impossible to say what options you might have in this regard.