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 Still great, I just don't use it anymore since I feel it's outdated and loading speeds are better nowadays.
portable clothes washer and dryer: they're both 20 years old now and i bought them used on craigslist five years ago and they've already paid for themselves multiple times over. regular sized mobile washers and driers are normally 2x the price of traditional washers and driers, but they're 1/2 the price used; i got lucky and mine were 1/4 the price.
mobile clothes washers and driers are great because they don't require any special electrical, water or drain hookups that traditional washers and dryers require so you can use them anywhere where there's electricity, running water and a drain. i hook mine up to the kitchen sink for the washer and use an exhaust hose w a window for the dryer whenever i need to do laundry; then i use their built in wheels to put them in the closet when i'm done.
their regular sized capacity means that i can wash the same tings that that a traditional home washer and dryer can do, but since they use regular 120 volt electric plugs instead of the special 240 volt washer/dryer plugs, they take longer to finish; but still worth it, especially in a rental situation where you can't install traditional washer & dryer electrical and plumbing hookups.
they're not advertised much in the united states and i think it's because the profit margins are bigger with the traditional home washers & dryers since portable ones require more more machinery and electronics to clean clothes, whereas the traditional ones rely on your home's specialized power grid and plumbing along w simpler machinery.
they're more common in places where 240v grids aren't as plentiful like latin america and asia; which is where i learned of them.
also know that well known appliance company branded ones (eg magic chef, black+decker, maytag, lg, speed queen, ge, etc.) are the same as the off brand ones, but w a company logo and price tag attached.