If you purchase small potatos, like New Jersey, they can be stored in a dark cupboard, and will last a couple of weeks. Prior to them growing eyes, or going bad, you can boil them, and refrigerat them, giving them a further few more days of usage.
I totally understand re supermarket plastic packaging. I will take them out of the plastic packaging once I've purchased them, and bring them to the boat loose.....
You choice of ingredients sounds tasty. I also use herbs and spices and not jars of sauce!