A demon Solo can combo UP to 1500 Damage.
But it usually don't hit that much,
The average damage use to be like 300~800 if you keep distance and keep yourself in the diagonal!
if you are equiping a good set you can reduce the average damage to with energy and fire defense imbuement, you can reduce the average damage up to 200~600 if you have a bonne fiddle, you can avoid life drain, and garlic necklace is welcome also..
if waste is not a problem, use mighty rings and stoneskin
and you can reduce the max distance damage up 500 .
so it's safe have a little bit more of life..
to damage I think SD can help a lot to achieve your goal,
So lvl 45 is a nice approach. as rp or mage,
EKs need at least lvl 80 potion and imbuements..(if you have a druid it's not solo. so doesn't count)
But if you plan hunting safer it's better over 120 as RP (because u can use prismatic ring), and over 200 if you are mage in easy resps. dont expect to lure more than 2 demons and be fine, always taking care about your life, and ready to mana shield if its necessairy.
in these levels its possible even to have profit already.
If you want to be hardcore as Itexo, you can try even less than 30 but you will deserve a lot of lucky..