My EDC doesn't have much redundancy. Although the phone's backlight does put out enough general illumination to be useful as a second light. Probably there is a way to start a fire using its battery, but I am not going to experiment on my own phone to see what's needed. (Some thin wire or steel wool, I'd guess.) Maybe I could slip a scalpel blade into the battery compartment, too. Build a basic kit around the phone.

The lack of redundancy doesn't bother me too much, partly because I figure anything which wipes out one piece is likely to wipe out anything else I'm carrying. I am more concerned about what I don't have at all. For example, no writing paper or implements. That's partly through not having a pen I'd trust to work after long neglect. No duct tape. That's partly because I am not sure how useful it would be after being unwound from its original spool, rewound onto some EDC former, then unwound and applied. Also because I've never thought to myself, "If only I had some duct tape".

Money isn't a limiting factor for me. It's more down to weight and bulk. I have a traditional tobacco tin PSK, the smaller tin, but it's too big for my trouser pocket. It lives in my jacket pocket, but I don't wear the jacket in summer, or indoors in winter. Availability is a factor, too. I don't like to buy stuff off the internet, because it's not convenient to have it delivered, so I tend to go with whatever local shops stock. Which is often inferior. Once or twice a year I have an internet binge.