I'm not that great at valuations, but in my opinion the pick of these three by far is onlinesavings.com.au
Overally i think onlineXXXXXX or XXXXXXXXonline are a bit parse and old hat, however people do actually use the phrase "online savings" as in "online savings accounts", as they also do for "online banking", which should give this one a bit of value.
The other two I think are less likely to be used by people as an actual phrase.
This to me makes onlinefinance and onlinecareers a case of "NothingwordKeyword", with no more value than ourcareers, yourcareers, mycareers, findcareers, greatcareers, etc. All are brandable (as some of the singular versions have been), but don't hold a lot of value as just a domain.
Just my 2c - I may be wrong!