Boxtops has made a very good point. Isn't there something called "pet plan", where you can pay in installments? I'm sure someone would help you out. No vet would just say no, and see the poor dog suffer.
Ah, where's Rolph Harris with his blimmin Animal Hospital, when you need him :)
Oh, and I don't think Welshi was "looking down on you", either. I think you read it the wrong way, due to the exclamation marks. She was just being nice and trying to help... :-)
Good luck!