Just to clarify,
USC CS is ABET accredited, the CSBA is half business so it makes sense it is not. I do not see CS at UW under the ABET accreditation website, but just did a quick search, if important to you, here are links for that.
USC:
http://main.abet.org/aps/AccreditedProgramsDetails.aspx?OrganizationID=165&ProgramIDs=
UW
http://main.abet.org/aps/AccreditedProgramsDetails.aspx?OrganizationID=61&ProgramIDs=
CSBA is one of the most in demand majors at USC, and the CS program itself is very strong. Obviously CS is strong at UW too. I don’t think you will find more money, so it just depends on how much student wants a certain school, a certain college experience and how much you want to spend to provide that, or ask your student to be on the hook for whether that is during college or after college.
Personally, I think where one attends college is very important to where they end up in life, the connections they make and the jobs they land. They don’t get a do over of those four years, after that it’s on to real life and all it holds. I don’t see it as all about the money, but that opinion varies by person and family situation obviously. There are also differences between a public and private, but you have two excellent choices. Assume you are direct admit for CS at UW? (Just to be sure.)