Please help save Biscuit Boy

My daughter, Amelia, decided that for her senior project she would do something amazing and kind. She started fostering kittens and helping with the adoption events through Animal Keepers at Petco. On September 4th we got our first batch of kittens and have helped 54 kittens get adopted. Over the last 12 weeks she fell in love with Biscuit Boy (he would jump on your lap and knead you like a biscuit). She decided to make it official and adopt him on Saturday. Biscuit was always the runt of the litter weighing only 2 pound at 5 months old. He got his second round of vaccination shots on Saturday and by Monday he was no longer the same kitten we started with. He stopped eating and became lethargic. We took him to a vet on Tuesday(I will not name because I have nothing nice to say about them). They told us he had rabies and to put him down. We knew he did not have rabies and that was not an option. He then had a seizure as we left the doctor, so we turned around for help. They again said they would keep him and put him down. We took him home. On Wednesday we took him to AVETS. He was having a seizure when we arrived, they immediately gave him an IV. They have run several tests so far and are planning on doing a few more. He had 13 seizures on Tuesday, since being at AVETS he has had only 3. They gave us a bill estimate and we had to put down a deposit. The estimate was $8,000. My daughter is heart broken and devastated. They say it is FIP. She said Biscuit deserves a fighting chance and if he was a human the first vet would have helped right away. Please help us, help Biscuit have a chance at a normal life. Thank you.