I'm on the side of wait and see next year and save your money. I have seen many weird things happen when it comes to tree resilience but never a beech with crown dieback ever come back. Now what i have seen is homeowners dumping thousands into a tree in hopes of res-erecting it. Not to mention this looks like a very old forest grown beech that no longer has the forest around it? Nor the soil microbes,nutrients,fungi, deer turd bunny pee you get the picture.