The hard part is getting from 98 to 99 only diablo baal and nilithak give you exp at that level.
Getting to 98 isn’t too bad but 98 - 99 … 
is a different story, that’s why the robots always win.
Easiest way to get 99 lvl is go to forums and claim exp cost reduction.
I always see this and cringe. Should be countess runs to get the runes needed for stealth and leaf. Also, how do you finish Tristram at level 15 then start at level 15 on Tal Rasha’s tombs? You’ll gain more than a level doing the entirety of act 2. Also, why is “complete Right of Passage” even on the list. That’s a given if you’re doing Baal runs.
Now that is refund worthy. They better not. If I want to run pindle over and over again, I should be able to. This is freaking D2. That’s the point.