I'm sorry for your loss of Pogo. The cost of the interferon highly depends on the generosity of your vet. My vet bought a vial of the human Interferon-A (the stuff that you give to the cats, except BEFORE it's diluted), and made me a whole saline bag full for $20 a few years back (he froze the rest and sold it to other customers, presumably). It really shouldn't cost MUCH more than the cost of the actual vial of Interferon-A (brand names can be IntronA or Roferon-A) and the cost of the bags of saline, which, depending on what pharmacy your vet uses, will vary. My local Pharmacy says a vial of NON diluted Roferon-A (it;s a powder) goes for $208.00. Mind you that makes several BAGS of reconstituted diluted Interferon for oral use in pets. I forget now how many bags it makes, my vet said they can dilute it once, and freeze it, and then off that dilution, they make more bags full. Someone else on the list could probably tell you for sure how that works. I used to have the Island Pharmacy webpage for it but can't find it now.
Here are the manufacturer websites: http://www.introna.com/introna/index.jsp http://www.rocheusa.com/products/roferon/ Phaewryn Please save Whitey! http://ucat.us/Whitey.html VT low cost Spay&Neuter, and Emergency Financial Assistance for cat owners: http://ucat.us/VermontLowCost.html Special Needs Cat Resources: http://ucat.us/domesticcatlinks.html