I ran into a similar problem. The feed stores that normally carried Sulmet or Corid were no longer carrying it. I talked to the manager at
TSC and they said they only had the pills, and don't feel bad, I wasn't going to spend $64 either. I went in to double check and they had the Corid 20% powder, ?!
And they had an empty slot for Sulmet, so I'll just keep chcecking until they restock. For now the Corid is doing wonders, at 2+tsp per gallon every morning. You can order Sulmet and Corid online for roughly the same money as purchasing it in the store, with shipping. If you really can't find it locally, order it, you'll spend about the same $. Time is not on your side however.
I think it's odd that we all have this issue right now with similar, non traditional symptoms, could this be a new strain, or a mutated strain? Yikes

I was thinking about dosing my girls with Sulmet in a few weeks, just to kill off any cocci that hung on and became resistant to the Corid. Poor little hens
