So sad! I wish you the very best what ever you decide.
One thing I would ask/consider: if you went a head with the surgery, would you still have to pay that huge amount if Bassett didn't make it? I had a dog that had surgery and didn't pull through and it took me forever to pay off the bill and it was nothing like this will be.

There's just so much to decide. I'm behind you and support you what ever you decide.
(((HUGS)))