Why would they even grade that? How could it even GET a grade with no shrp design features, let alone a field that is really non-existent. The poor OP is out $50 that he'll never see, since he was uneducated enough to open his wallet and send it in.
Struck through grease is a mint error. So it can receive a straight grade. The amount of grease determines the design features. The heavier the grease the less details. It also will affect the fields. I can see people paying $50 for this coin but I am not one of them. It needs to be an extremely strong grease filled due to grab my attention as it’s a very common error.