Edited by Manor Hatchery - 12/13/16 at 8:19pm
I prefer Boone's Feed or Blacksmith's Corner, but those are a bit south.
I would probably suggest visiting the closest feedstore to you so reupping can be as convenient as possible. If you don't like that feedstore then go the next closest.
Pretty much any actual feedstore will carry something you can use so any visit won't be wasted. You can always call ahaed and make sure they carry what you want (for quail, hihgh protein gamebird crumble or Turkey starter).
Redbarn definitely carries GameBird crumble and (most likely) Turkey starter crumble. Should be around $25 (give ore take a few bucks) per 50lb bag (enough to fill my two 5-gallon buckets from Lowes to maintain freshness and keep pests out). Just make sure to get at least 24% protein content, preferably 28% but that can be a bit harder to locate sometimes.
I've only ever done 24% and 28% myself based on the info on this site (and others). http://www.thepoultrysite.com/articles/473/feeding-quail/
I would think that 21% would be enough but I don't have enough experience to say.
Have you seen any issues with egg production or anything?
Mine aren't laying yet, I just got them...think they are still stressed from being moved and don't think the previous owner gave them enough light. However, a friend of mine had coturnix quail and just gave them what he was feeding his chickens, I think it was like 16-18% protein and they layed eggs every day.