I've had mine passed 30 days and I've had no option for an upgrade. I know for sure I haven't spend 70k with them but someone on tumblr did say they spent 70k and got it that way. On TTing they didn't specify.
the only shop i know of that upgrades is nooks cranny, but i dont know if it upgrades past that, i thought interacting with label 3 times will make her upgrade the able sisters with her accessory shop in it or same thing for the shoe guy but so far i dont think so
