Undergraduate Student Enrollment, 2014-2015
UVA: 15,669, VA resident (68%)
UCB: 13,330, CA resident (65.5%)
Who favors whom?? It is about the same!
Tuition Cost for Undergraduate Student, 2014-2015 (according to CollegeData)
UVA: In-state: $14,468; Out-of-state: $43,082
UCB: In-state: $13,431; Out-of-state: $38,139
Citing the CMU admission data is relevant because CMU is in neither CA nor VA. Therefore, it could be considered as a top university in CS/Tech with no preference over students from CA or VA. It is a measuring stick.
As to the 529 plan, it is money out of the student's pocket, not from the thin air. Therefore, attending UVA is not FREE for VA residents.
Finally, comparing admission data from a private high school against a public high school is not the point here. That would be an apple vs. orange comparison. DC metro area has a lot of private schools for the elites, including the one which Obama's children attended.