That Potter's Choice shino is not a true shino. It's similar to a shino in that it's kinda orange, but beyond that it's not really even close to the real deal. That's not to say it's not a nice looking glaze, I just wish they wouldn't call it a shino.
Cones have become much more expensive since digital kilns came into fashion. But you won't need to use them forever. Once you've used them to confirmed the soak time needed to get to cone six, you can stop using them. Keep them around in case you run into issues in the future and need to re-confirm.
to be honest, anything in american ceramics called a "shino" lacks the geologic pedigree to be called a shino--but semantics.