I've found that vets often charge much more for meds than what you can find online. Sometimes, though, we're forced to get the meds through the vet. I think for any kind of drug that has to be given on a long term basis, it absolutely pays to check out the internet for better pricing.

On a side note, I quite regularly get refills of a prednisolone (5 mg) prescription for Peanut. From our old vet, 30 pills was about $5.00. From the new vet, it's about $15.00 - for the same exact pills, by the same manufacturer, same dosage - everything. So, prices on pills and meds are really all over the place at vets' offices.

Hope the meds clear everything up soon for your crew!