Our fees are anywhere up to $600. One of the other national groups is the same as ours. There is one that sometimes charges up to $3,000 (yes, I have actually seen that).
If a rescue is fully vetting and taking care of all presenting medical issues on their foster pups, the adoption fees rarely will cover the cost of vetting.
To see an explanation of YHR's fees, here is a link. It might help to understand the fees of this group you are referring to.
Yorkie Haven Rescue Adoption Fees