From my own experience recently leveling a multi-spec DoK:
Gearing for both is not very hard unless you're in a big hurry to hit 40. Leveling is fast in ROR
Budget your Emblems (Scenario currency) for vendor weapons.
Medallions (RvR currency) for heal(salvation/dark rights) set.
Easy PQ's for Coins (PvE currency) use them for lifetap(grace/sacrifice) set. Alternatively, you could do more Scenarios for the scenario set but they have a dps focus.
I can say the recent addition of the mastery spec swapping makes switching specs very easy. Grab the ClosetGoblin addon from Idrinth's Tools website (https://tools.idrinth.de/addons/) and gear swapping is easy too.