The post office doesnt impose a minimum number, for the record. They don’t care, but don’t like sending them at all. However, its pretty expensive, so if you aren’t paying through the nose for the shipping, the seller is probably subsidizing that cost and that’s where the minimum comes from. I just ordered a trio of specialty breeds this past spring, but the place I bought from sends individual birds if you really wanna spend $70+ for one chick.