Well, lets see what I can remember.
When it comes to artifacts you can buy everything needed for either bounty points or Atlantean Glass (which can be bought on auction or farmed). You need the artifact encounter credit and 3 scrolls, which can all be gotten for bounty points.
(This at a place called Ruinerar of Atlantis, just inside of the atlantis zone in)
For masterlevels you need a credit to pass it. But you can either do the encounter, or buy the credit for bounty points.
Pretty much, anything can be gotten with bounty points if I remember correctly.
There is also the other type of levels that we need, what the hell are they called? Champion levels! Thats it. They are somehow connected to the champion quests, which are good xp and natural to do while leveling the last couple of levels.
Xp for champ levels, master levels and artifact levels can all be gotten by RvR if i remember correctly.