What's the cheapest thing you had bought that by the end of its usefulness made you say "wow, this was worth a lot more than what I've paid for!"
Mine... My Xbox 360 slim only costed 129 euro back in 2012 and to this day still work like brand new, you would think that the disc drive would stop working but no. Never had the need of open it or clean it's insides. Still great, I just don't use it anymore since I feel it's outdated and loading speeds are better nowadays.
Victorinox Swiss Army Knife. It's still kicking. The amount of times I've used it, it saves so much time than looking for the proper dedicated tool.
A metal wallet. Definitely worth it if you don't carry a lot. Mine is maybe 10 years old now or more.
3+ year old used Lenovo Thinkpads, these things are great if you need a budget laptop that's not for gaming. A lot of companies lease them. When the lease expires you can get them very cheap because they flood the market.
General Military Surplus. We have a shop a few kilometers a way that sells surplus. They get in brand new stuff all the time. Still in packaging. It's built well. Keep in mind military surplus isn't just in the field stuff. Laptop bags, shirts, blankets, hats.
A pet. Worth every penny. Got my cat from a shelter, he's been there for me through thick and thin. Gives great hugs.
Trying to convince mine, she keeps buying these expensive cartridges that she ends up throwing out after a few times or they get left out and their little soap bars fuse to stuff. They suck.
ebay is a good source though more expensive, places like marketplace often have decent deals, check out electronics recyclers and wholesalers, if you have any. Those are generally good places to look.
My first thought was some military gear as well. A scarf or travel utensils or bag or something. Actually even the gloves I got are probably over 20 years old.
Rescued pets cats be priceless, though keeping them fed and healthy and happy can cost a fair bit.
no the alumawalletesqe things have basically a plastic accordian inside. Thats what dies and its all one sorta unit. The one bej linked looks like it would not have an issue being it is a sort of card clip almost.