I know that Walmart here fills out pet prescriptions so I'm hoping it's cheaper there. I'll know for sure next week but I'm pretty sure he said prednisonePrednisone is very, very cheap.
Retail pharmacies don't charge more for "pet" medications. A medication is a medication. Just make sure they do accept and fill pet prescriptions. Also ask nicely if they have a discount card that works for pet patients (Just Rx for Pets is what we use in the chain I work for, just as an example)
Also prednisone and prednisolone aren't the same thing, so make sure you get it strait before calling a pharmacy to ask for a cash price on it.