What is the ruling on dealing with a website that markets programs for $0.50 and 10% of the value of each sale, with profits being withdrawn via PayPal or bank transfer?

As for the fixed commission (0.50), there is no issue with it. As for the commission that is a percentage (10%) and combining it with the fixed commission, it is permissible according to the view that allows the wage to be a percentage of the profit or the sale price, and allows combining a known wage with a percentage of the profit.