602 paragon here with ~80 hrs played, run groups with exp/heal monk (actually i'm playing one hehe) 55-60 grifts. I can easilly imagine that without afking in town, doing bounties for reagents, farming keywardens and playing sometimes solo i could be well in 800 range with the same amount of hrs played.
Actually if you're playing monk after crafting exp gear, getting RorG and gambling Inna's pieces solo rifts, bounties and so on just aren't worth it becouse your ancient weapon will be crafted (born's) and amount of shards you get in 55+ grifts will gear your dps spec extremly fast. So you just farm towards 800 paragon, meanwhille leveling gems and getting gear for pushing grifts solo.
P.S. Got bored at paragon 600, might farm some later))