This is a really interesting thread and I find it curious that the finance/economics degrees seem to be the ones in focus.
As a sport scientist, I have to undertake a MSc in order to get accredited status, something which is required for all the jobs that aren't glorified PTs. Additionally undertaking a one-year MSc gives me the chance to network with employers more voraciously than I did as an undergrad.
I'm not saying it's right for everyone, and I've taken a year out (yes, working and gaining experience) before applying for it, but in the sports science field I think that a MSc course is certainly not a cash cow...finance degrees where they think it's acceptable to charge ludicrous amounts, may be a completely different story!