I think that's a far more useful way to look at it than a simple binary of skilled and unskilled.
I'm a bit fuzzy on how the continuum really relates to wage, because ultimately it's a question of supply and demand.
I guess if you have a rarer skill because it takes longer and is harder to acquire proficiency at, demand will be higher so you won't go for jobs that are easier to acquire the skill for, thus, jobs with a bigger supply of workers? And so that drives the pay offered.