Anyone know why this +1 max dmg charm is required level 77? Thought it was comical that plain +1 is 77 but I have bonus and +3 etc all lower level

yea well its because

The +1-3 has to be prefix or suffix
And this one would be the other one either prefix or suffix, giving up to +4 max

So basically, because it's the suffix it has level 77 req even though the same thing as prefix is level 20?

Yeah would have to actually check it out, but that is my guess. I don't see how that can be otherwise. Go Maxroll or Arreats or whatever website has this intel and you will have a 100% sure answer