I have no idea about this operator or this job but my observations of the skydiving industry is that it should be able to afford to pay a decent amount of money. I certainly wouldn't work for them for anything less than well above the equivalent of the award. Dropping skydivers is not without risk and demands a careful operator and pilot.
That said, it is not up to the AFAP to check what the contract is about before putting up the ad. Ads for jobs on AFAP have or were free to place as a service to pilots. It is up to the pilot to determine whether the job is any good or not. Caveat emptor has always applied in aviation and probably always will.