I know people who have side businesses repairing computers, smartphones, cars (main business), even selling homemade foods. Most of these people have a do it yourself mentality. They have and are able to make money out of it. I do not have time to use my PC maintaining skills to earn money. Plus I can not fix apple computers. I ONLY know pc.
However, it is very liberating to know exactly how to fix most common issues with a computer, and know what parts to buy if it can not be done at home with tools on hand. I have the same outlook with my car. I do not do to a mechanic and say my car is doing blah blah… NO I tell them "I need a new radiator this one is leaking." Or I say "How much is it to change a head gasket? I ask for services I need, or want. Very liberating. Once the mechanic broke my clock spring. I smelled something fishy when he blamed it on me. I only went to him for oil changes. So called my long time friend who helped A LOT with my education in car maintenance, and how to diagnosis certain issues. I asked him in English how much is a clock spring for my model of car. He told me it is 180 bucks new from KIA, not OEM. The mechanic seeing me drive a large car quoted 400 bucks. When I told him to stop cheating me. He then said it is 180 for a used unit. He likely could source one for free from a friend or a junk yard. I told him that look you are lying it is 180 for a NEW unit. I never went back there.
Second hand items are another funny thing here. I will only say this. If prices are dirt cheap by from them you can trust them. If prices are slightly lower than the cheapest new items on the market stay away. Or if they are very cheap but they keep pushing you to buy a "new used item" run away. As for second hand goods you have to know the market. I was looking for a cheap monitor for my boys. I already new for a 24 inch monitor I could grab one for 95,000 won. I go into a shop. The dude sees my note 10 in my hand. He sees me using English with my wife. I ask for a old...very old 27 inch monitor. He said shiiiiiiip chil man won. Basically, he was seeing what I could afford by saying onnnnnneeeee hundred seventy thousand one! I laughed and told him that it is a rip off. I said thank you and left.
He could have made an honest sale an gained a loyal customer.
/tata