Son had a nasty rattle while driving his car. Shock grommet was rotted away and shocks needed replaced. Was like $400-$500 for a local mechanic to do it. I talked him into buying his own shocks, going online to purchase the materials, and borrowing the tools. I pointed him to the appropriate YouTube videos for his make and model, and he did it for about $90 total. Same for when he needed his tie rods replaced.

My daughter's car wouldn't start intermittently last year, and I happened to be in Utah. It started up for us so we drove to O'Reilly's and they did a test, and sure enough, the starter was bad. We bought a rebuilt one from them for $120 and replaced it ourselves, following instructions from a very detailed YouTube video. It was very complicated, but we followed the directions exactly. Probably an $800 fix from a shop.

Daughter needs new rear brake pads and rotors. Again, was a $500 job, but the whole kit on Amazon is $73, and YouTube has a good video for it. I'm not footing the bill for them, and with how tight money is now days, just so much better to do it yourself when you can.