Woke up today and the house was real cold. By mid-morning we'd figured out the furnace wasn't working. When I got home in the afternoon I started troubleshooting it, and by about 4pm I got just far enough to figure out it was probably the igniter. I didn't have time to do a hardware store run to buy a replacement since I had to get dinner ready, so we called a repair guy to come out. When he got here I told him I thought it was the igniter.
Aside from the fact that my house has heat again, the good news is that as he was packing up the repair guy said "You were right, it was the igniter! You want a job?" I got my laughs in before receiving the bad news, which was the nearly $200 charge for installing that $15 part.
I keep telling myself the $200 is also for not having to go to the hardware store, for not having to put myself through the headache of figuring out how to replace the part properly (I've never worked on a furnace before), for not having my wife pissed off and stressed out from having to watch all three kids while I did all that, for being able to sit down and eat dinner with my family, for supporting a guy who works to support his own family, etc. Sometimes remembering the hidden value makes it feel more worthwhile.