It might be a "contract" but that's a long-term contract, if you honestly made more than $30k doing this, you are doing extremely well.

$250-300/day avg would be about right for the airframe IMO for just a regular daily contract guy with no commitment, but your case I just can't see the "double what a salary person would make" scenario. I just don't see someone wanting to pay that much considering the airframe involved.