Sorry to hear of the setback, Joe.
I'm not liking your choices much. Only two viable options, really. I can't see you giving up Maxi, that just wouldn't be right. So obviously, euthanasia is out as well. So that leaves us with a vet bill, and/or amputation.
We're all here for ya, Maxi. Tell that hard-headed master of yours to let us do what we can. You're just too darn cute.