re: Am I overpaying for oil-changes?

Not really a way to beat without doing it yourself. Maybe can squeeze $20 out by shopping around, but you need to factor in drive time between the shops, as well. There’s also a huge advantage to doing it yourself. You’re less likely to screw it up unless it’s your first time.

Just make sure you’re honest with yourself about your time. On just about every DIY job, the time is much more than planned, as it starts from the minute you walk out in the garage, gather the oil/filter, pull out the right tools, lay down cardboard, etc. If you start a stop watch on your phone, and then end it when you finish washing your hands, it’s usually MUCH more than you think (It also depends on how careful you are, or if you are focusing on moving quick). Then, just put a fair price on your time if you were working OT or something else, and you’ll get a more accurate estimate. It’s probably a wash at the end of the day, at least for an oil change.