On the question of US tax payers subsidizing foreign students (whether state taxes or federal) - it is probably more effective than foreign aid in terms of promoting US values and interests, it helps present a greater diversity for US students at the schools, it broadens and deepens discussion and intellectual rigor in the classrooms, and it adds to the richness of American experience. Universities already actively recruit foreign students in their general populations and while they mostly pay full tuition, that is still a subsidized situation as almost all universities take tax money to some degree. Many of our essential businesses have relied for a long time on a flow of college educated foreign employees to fill their needs - as anyone who has spent time in hospital may have noticed (nurses and doctors for example.)
So yes, I would say it is money well spent, and represents a 'rounding error' in terms of the total tax revenue at either state or federal level.