Hello! Thank you for playing!
Yeah, I know, having to visit the same shop over and over again to buy more than one Item is pretty exhausting, I will definitely fix that in the future. And auto unequipping the item is a great idea, it would make it much easier. Thanks for the suggestions!
As for the savegame location, I believe it's somewhere in C:\Users\yourname\AppData\Local but I'll double check on my computer at home tonight (I'm typing from my phone at the moment).