Those of us who pay full freight choose to do so (in almost every case there's a less expensive option, just not one we want). For us, our kids probably wouldn't be accepted to the one or two VA colleges they'd want to go to so we looked OOS.
This describes us. Our DC is in his 3rd year at an OOS private SLAC. Cost is 34K (includes a "scholarship"). We would have been full pay in state if he had been accepted to a public school he liked, but it didn't happen (in VA). This decision means about 60K more over 4 years. We would be enjoying more meals out, travel, new clothes, house renovation, etc. if this had not happened. Crossing our fingers that he is gainfully employed after he graduates.