A couple more since this thread started...
I bought a 62 Caddy for $1500 because the guy said it just died one day and he couldn't get it started. When I was negotiating, I noticed the distributor cap had popped off and was crooked. After I gave him the cash and he signed the title, imagine his frustration when I put the cap back on, fired it up, and drove it home. Fix = free.
I snagged a 74 maverick for $300 because the guy was frustrated with the electronics. He had replaced the solenoid, the alternator, the starter, and the battery, and it just wouldn't hold a charge. After jump-starting it and getting it home, I realized he had put the alternator wire on the wrong side of the solenoid. Fix = free.
In my current job (tool repair at Home Depot) I have amazed people with my "talents." They pull a lawnmower out of the garage in the spring and it won't start. I pull the bowl off the carb, drain the fuel, run a wire up through the jet, put it back together and it starts on the first pull. Of course they say they ran it dry last year, or used stabilizer, then I show them the tablespoon of water I got out of the bowl.
Just two days ago I had a guy bring in a top-of-the-line Honda mower and said it won't start. I pulled the cord and water shot out of the muffler. WHAT ARE THESE PEOPLE DOING?
Another one came in... it was an old Bolens string trimmer that would only idle. The guy had bought a new Echo but wanted to fix this one to take to camp. The muffler was just packed with carbon and oil. I grabbed a drill (which already had a 1/2" bit chucked up from another project), drilled a hole in the muffler, ran great. He asked me what he owed. I told him that we charge $60/hr and this job took me 35 seconds. I said "you owe me a handshake."
This is why I love my job. I get to make customers happy by simply using my analytical brain. One thing I will say about Home Depot... they recognize customer service. No boss will come to me and say, "you didn't follow procedure," or "you should have charged him the minimum $15." They say, "thanks for kicking ass and making a customer happy."