please help me help smigs to not be in pain

This is Smiggles. My younger sister got smiggles 13 years ago when he was a puppy and he's lived with myself also from time to time. He's staying with me atm while my sister gets through some hard times financially.

Ive decided to take him to the vet for a dental check up as he's been whining over his food bowel. Smiggles has had a few teeth out but now needs the rest taken out. He's under weight and getting him to eat is a struggle as he's in a lot of pain. His front teeth wobble and the vet has told me that he has infections in his gums.

I myself am in a rough spot financially atm so the $600 quote I've been given isn't ideal but I can't stand to watch smiggles be in pain and go hungry.

Any help would be much appreciated!

Smiggles is getting older but being a chihuahua he should live till 20. he's still got energy and life in him but I know he would have so much more with these rotting teeth out.