Ok, I accept your second point. Regarding the first... If there was an unskilled labour that, by itself could produce $100/day profit for a majority of people,

Ok, I accept your second point. Regarding the first... If there was an unskilled labour that, by itself could produce $100/day profit for a majority of people, then you wouldn't have any $10/day labourers. This $100/day profit is only possible with the value added by the skilled labour. It is like this everywhere. For example, the artist who made the facebook logo only got paid in the hundreds of dollars yet the facebook logo produces much more than 10x that in profit. Yet, without the value that the facebook product adds to the logo, it would have been worthless. You wouldn't argue that the artist is underpaid.