Feel like I got ripped off and dog euthanized

My grandpa's dog i care for a lot was was lethargic and sick so I took her to a vet and they found a cyst in her womb and wanted 10,000 to spay her to get rid of the infection my grandpa told me to have her put down which was 1k. She was so sweet and would hop in excitement to see you. I was looking online and the same surgers was 3 times less at other vet clinics and she told me she didnt feel safe relasing the dog in her condition. I'm actually devistated she was so sweet and only 7.