green cat puke!?

Hello everyone,
my little cat gavin is normally very playful and has a good appetite. the day before yesterday he wouldnt eat his dinner, all day yesterday and today he has been lethargic and vomiting. it started out clear, then yellow and now green. I took him to the vet last night and she said she was worried he may have swallowed something (string/toxic plant etc.), she gave him shots of fluid because he was getting dehydrated and recommended taking him to the emergency 24 hour vet for xrays and possibly surgery! I cant afford to do that (500 dollars for xray, tests and hospitalization plus another 500 for surgery!)
has this ever happened to your cat? any suggestions on what I can do to keep him hydrated at home until he (hopefully) can recover? Any chance this could just be some crazy hairballs? should I try giving him cat grass?
help!?

thanks,
jd

Go To The Vets!

Take your kitty to the emergency clinic ASAP. If you talk to them in advance about payments, chances are they'll work something out w/you. Don't let your cat be sick because of money. There's always a way. C'mon now, get moving! :)