It sounds like you're offering a choice between paying nothing but exposure or paying just as much as for the most senior experts.

If someone is less good, pay them less, but still a living wage. If they're not worth that much, and you don't want to train them to be worth that much, then don't hire them.

But that's all assuming the price of a contract is roughly proportional to the cost to implement it. Any "absurd markup" is a totally different issue.