I like having tools in my home, don't get me wrong, but storage being free is an illusion. I still think the cost to be worth it.
You're spending mental power indexing all the things you have. I assume you pay for your dwelling, dollars-per-sqft is a thing to consider.
Doing the Amazon route (which is exactly what I do) means I know I have every cables I could ever need within 24 hours. And I don't have to remember where I last put it, and I don't have to deal with knotted cables, and I don't have to wonder when a thing doesn't work, is it the cable?
I'd say Amazon is not necessarily a guarantee of that.
Instant access to useful items is valuable. Think of it like... caching for tools. I like having items I need within reach. I'd love a bag like Hermione's in Harry Potter.
Waiting 24h is a lot if you're in flow and you want that thing _now_ dammit!
Even then, it's most likely even more expensive, because if it's just an off-the-shelf HDMI cable, you'd probably have one around. Look for the cheapest SCSI cable, if you don't think so.
I don't want to say 'store everything', but just backordering stuff is much more expensive in my experience.
Video game output cables are already hard to find for cheap.