Yes they fell in prince since they were released, but they are still worth using your self. Weather your farming or not there are lots of great areas to us that in.
I'm not all that worried about XP...I'm lvl20 I'm not planning on changing my secondary again...and I have 30 Skill points...so I don't really see a point in using it.....
Those never seem to last as long as they say they do. They're still selling fairly high...but would definitely be managable if you could have a group split the cost.
