So, you wouldn't be satisfied, if I can bring you tons of customers, for the amount of money you are asking?
If you are charging logo 100$ a piece, and I can bring you so many customers, that you need to hire few friends, you wouldn't do it?

Why do you care, how much I charge for my services of finding people, to buy your service. You are being paid for what you are asking for.
There's either you work it 1 customer in 10 days, or I bring you tons of them. This is mutually beneficial.

This same thing applies when you work with designing company.
While you are designing 10 logos a day, and being paid 5$ per hour, they are selling those 10 logos 1000$ per piece. So, hows this any different? You agreed to work that way.