There is a reason why plumbers, electricians, car mechanics and other tradespeople charge so much. Working on other people's stuff is stressful!
A friend of mine recently asked me to help him install a mini-split system A/C unit. I had tested these units when I worked at Carrier - but that was 40 years ago. I installed three units at the lake house, but that was over 15 years ago. I installed one in my garage, but that was ten years ago. I just don't do this stuff enough to stay current - and they change things, over time, like refrigerant types.
But if you know how air conditioners work, have a vacuum pump and set of manifold gauges (and know how they work) you can install one, if you read the directions carefully. It isn't easy - you have to punch a 3" hole in the side of your house to run the refrigerant lines, electrical lines, and the condensate line. Oh, you'd better be pretty good at wiring to code as well. So on a scale of one to ten, where one is changing a light bulb and ten is replacing the engine in your car, this is a solid 6 I think.
But it was stressful. You see, if I am installing my own unit and somehow mess it up and the unit is wrecked, well, I am out about $1000 and its my own damn fault. I cry in my soup and move on. But someone else's unit? Now they'll hate me forever! Or suppose I wired it wrong and it burns down their house? Then I get sued.
There is no upside on this. The install went OK, and we parted ways. If you succeed, you are no hero, if you fail, you are the villain. It is a heads-you-win, tails-I-lose situation. Maybe you just saved your friend $500 to $1000 in installation labor. Don't expect eternal gratitude. In fact, expect them to pick apart minor flaws in whatever it is you did.
Another friend asked me to install some light fixtures. This seemed a lot easier, but it turned out one of the fixtures was an antique and something of a family heirloom. Well, not an heirloom, but it had nostalgic attachment. Problem was, it was designed to be hung from a chain, and they wanted it flushed-mounted. This meant enlarging the hole in the escutcheon plate to accommodate the larger thread of modern light fixtures and making other modification to the lamp. But I have to say, it worked out swell.
But again, the stress. It was a glass fixture - suppose I dropped it? From Hero to Zero in ten seconds flat. There is no upside really, in situations like this.
This is why tradespeople charge so much. You work on someone's car or house, there is a very finite chance something expensive will break - through no fault of your own. Many a young man has found this out the hard way, trying to change the spark plugs on their car (often unnecessarily) only to snap off a plug in the head. A $50 "upgrade" results in a $1500 repair. Sometimes it is best to leave well enough alone. The Waddington Effect rears its ugly head.
Problem is, Joe and Joesphine Consumer don't understand this. All they know is, they brought the car to you for a simple tire rotation, and you snapped off a wheel stud. Happens all the time in the tire business, yet people freak out.
The Do-It-Yourself movement took off in the 1970's when inflation drove prices through the stratosphere - often due to rising wages, which never kept up with rising prices - sound familiar? The problem is, a lot of people don't have the skills necessary to "do it themselves" and are unable - or unwilling - to read the directions or even watch a YouTube tutorial to learn how to do something. So they phone-a-friend for help.
And we all like to help out, although I have been flat on my back for two days with a wrenched lower back when I lifted the outside condensing unit in place. So then there's that. All that effort and all that risk and a wrenched back and.... well you don't do it for gratification or thanks.
I stopped working on other people's cars a long time ago. Not only does that put starving mechanics out of work, but it creates real risk. A friend had a rear wheel bearing seal go bad, and we had to replace that, and replace the rear brake shoes, which were soaked in differential fluid. Not a difficult job, but we had to replace the rear wheel cylinder at the same time. Unfortunately, my friend didn't tighten the brake line all the way - and I missed it when I checked. He called me ten minutes later and said, "My foot went right to the floor! I have no brakes!" It took only a few minutes to fix, but this is why mechanics have insurance - and why they charge so much to pay for that insurance.
So... I am out of the "can you help me out?" game, because there is no upside to it, and lots of downside. Trying to be "nice" is great and all, and helping out a friend is nice, too. But sometimes the stress and the risks involved are just not worth it!