FYI, Undiluted green is often scarce around here too. I've taken to ordering several gallons at a time from Rock Auto. It's less than $8 per gal for FVP or $969 for Zerex. Even with shipping it's cheaper than the local auto parts stores. Every color of the rainbow.
https://www.rockauto.com/en/tools/cooling+system,fluid+/+chemical,coolant+/+antifreeze,11393
