Asklemmy

Lots of kitchen tools are like that. Expensive probably isn't the right word, more like minimum acceptable quality. Restaurant supply stores are great for this: a restaurant owner won't buy the fancy brands, but they also won't get something that won't do the job right. When you get something more expensive than the restaurant supply store, you are mainly paying for cosmetics.

Food processors and mandolins come to mind: they are a pain to clean, so unless they work really well, you're better off using a knife.

Stock pots you can get thin, crappy ones from Walmart that will never let a large volume of liquid get up to temp without scorching whatever is touching the bottom. Better to save your money for something with thicker material.

Also,

• Cookie dough and ice cream scoops
• Instant read thermometers
• kitchen scissors
• cutting boards
• enameled cast iron (cheap stuff flakes off)
• measuring cups (do everything you can by weight, but when necessary, you want them made from steel, and with markings embossed on them, not painted)
• charcoal (and probably propane) grills. Poor quality craps out so quick
• probably a lot more things

For non-kitchen stuff, one that immediately comes to mind cause I just bought one is plant grow lights. Even with LEDs, you need a pretty high power output for it to be worth anything, and power output isn't even the right metric. I'm far from an expert at it, but a couple of things to look out for is if it uses a USB port, it's junk. USB (specifically type a) cannot produce enough power to be remotely useful for plants, so all those weird no-name brands you see are just annoying purple lights. Good brands will tell you the wattage, the PAR, the brand of LED used, and so on.