If white Macbooks had thunderbolt or USB3 ports they would be much more worth. The major leak for these devices is the lack of fast external connections. However, as a corporate laptop it's still good, and in some aspects are better than Air Macbooks: the built-in ethernet port and superdrive unit are welcome features in the daily corporate work.
I think if it's in a good shape, battery with a low cycle count, it would sell for around $600,00-650,00.