armory is showing you in ele so don't know how your resto gear is like. but core may not be that good upgrade with coming patch. core is not in my to-buy list now. of course it also depends on what trinks you have now. 2set bonus is not that great but it still is upgrade.
In general, I'd say T11 chest should be first on most people's purchase list; VP is the only way to get it. Once that's out of the way, it's a bit more open as to whether you want to get a second piece of tier, or hope baradin hold will be nice and spend it on something else.