rustysdream typed "Vets (and some other professionals...) should be ashamed for charging ridiculous amounts of money and make people feel bad if they hesitate getting the services."
dude, get a grip, as the son of a vet (and acquaintance of other vets) i can almost guarantee that the vet would arrange a payment plan to cover the cost of amputation.
i worked in my dads clinic or was called in for night emergencies pretty much my whole life numerous times there was a hushed conversation in the back room with my dad and no money changed hands. to this day my dad has NEVER had one of those cases pay him back whether it took a month or 7 years.
pets are a responsibility that require work and attention.
my feeling on reading the OP is:
-where was your fenced yard
-can you prove the dog was caught in a trap or just laying blame soemwhere else
-many many dogs have lived happy productive lives as tripods (i've also seen 2 legged dogs in pretty much any combination including a wheeled carriage for the butt)
-dogs that run "free" in the country get shot and letting them do so is irresponsible
sorry no sympathy here (well some for the dog)....