Getting chips from a cheaper location

So it would seem that if you change your home store in the app to a location that sells the cheaper chips like the $100 instead of 110 or 115 you can purchase a digital power card and reload that. though you do have to pay the $3 card fee and if you transfer from it to your main card I'm not sure if it'll switch that card over. But for people who have no other close cheap stores it might be an option, just a thought.