Edit: If you're disdainful of the "BA", you should be aware that there isn't any formal distinction between a "BA" and "BS", and every school decides for itself what type of degree to award.
Northwestern University happens to award BA degrees for biology: http://www.biosci.northwestern.edu/undergraduate/
> The undergraduate life sciences major offered in Weinberg College of Arts & Sciences is the Bachelor of Arts in Biological Sciences with concentration in one of five areas: biochemistry, genetics and molecular biology, neurobiology, physiology, and plant biology.
Is says a bachelor of arts, but looking into Northwestern's programs more, I think it is a type. I agree that $50K of debt for a BS in Bio would be reasonable.
In another direction, I don't believe MIT has any BA degrees, and a quick check showed that if you major in music, you get a Bachelor of Science degree (abbreviated S.B. at least in the '80s). Of course, you don't graduate from MIT in any field without doing a lot of physics and the calculus, plus some other science requirements....