How much are links on educational sites worth? Mainly student personal pages that are on the domain of the University's student?
Nothing, unless that they have high PR (preferably inbound) links pointing to them that will raise its PR. It is the same as getting a googlepages.com free hosting and making your own backlink. On the other hand, a high PR .edu link with lots of content on it will appear high in search engines, and is worth money.
No it's not. All things being equal a backlink from either a .edu or .gov domain is far more relevant than a backlink from a site such as googlepages.com