Help Tiger with his vet bills

4 years ago today, this little guy moved into our crawl space. Since then we have been watching out for him, water,  extra food in the winter and protecting him from other animals. Just before Halloween someone shot him in the leg. We have spent over $700 at the vets so far to patch him up. Unfortunately it has been decided that amputation is the best plan for him.  I have a quote from the vet $830-$1220.  We just don't have that kind of money to spend, if anyone could help at all I would be so grateful.