I would not describe myself as a prepper, but I do keep specific things in a pre-staged configuration. For instance there is always a bug out bag in the truck with basics in it, and second bug out bag in the house with more specific items that could become critical in a bad situation. The trailer is also always stocked with basics. I try to keep the truck with more than half tank of fuel. Always tried to get my kids ( and now grandkids ) to do that in their cars: "fill it up when the gauge hits 1/2".
My opinion is the most important part of this whole puzzle is to have a plan in your head to initiate a mission, and the flexibility to be able to change the plan in a dynamic ( and it will be ) situation.
The costco kit sounds interesting. I will check that out, thanks for the heads-up on it #1-N