Could it be possible to choose the fee? I don't mind to wait for days if necessary but having to pay 8 dollars for a batch withdrawal sounds awkward.
Currently they do not have this system of setting your own fees just like blockchain has it. Not sure for the exact reason though currently only 2 withdrawals type only they do have it. So either you can wait for few days as it is not urgent for you to transfer, so can check out after few days if the batch fees has being reduced then you can send it rather than sending now.