In an unrelated bit, I had no idea that Archaeology gave exp...
Quite a bit, actually. Each dig gives a % of your total exp (higher level areas give a slightly
higher %, if I understand correctly).
So, my DK says that it takes 1,683,600 experience to get from 80 to 81.
A successful dig gives 5,5000 exp, which is .325%. Rested exp will apply, doubling it. So it'll take about 300 digs to get one level (I assume this is true of any level). So from 20-85 (64 levels), it will take about 19,200 digs. Cut that in half if you only dig when rested.
A successful mining job of Obsidian gives 2,200 exp, a much lower % of my total, and lower tiers give less. So while I could level by just running around zones getting ore/herbs, it would take much longer. Each would give me less exp than a dig, and I have to rely on luck to actually find them. Not so much an issue at lower levels, but can definitely be annoying higher up. Of course, you'll probably mine more per hour than dig at lower levels, but once you get an epic flyer archaeology is super fast.