Changing the rear shocks is a piece of cake. Take a look where the upper nut resides, and where you access it, and you can determine if you want to do that job.

(Guessing you have a McPherson front, and a trailing arm rear.)

Doing the front struts isn't too bad, but you'll need a spring compressor. One possible thing you can do is to remove the entire struts and take them to a shop to change out the strut insert. That might save you a few bucks, but it sounds like your mechanic is taking care of you. (Those maintenance prices sound very reasonable.)

I only made one mistake when I did my suspension. I didn't tighten the nut tight enough where the strut screws into the strut housing. I heard "clunks" when I went over bumps. I went over every suspension nut & bolt (sway bars, upper & lower control arms, etc.) I could think of, but couldn't find anything loose. Attended a BMW CCA "tech session" and the mechanic immediately identified the problem from my description. It took about 15 seconds/side to tighten them, and the problem was solved.. Learned a good lesson with that one...lol

The car looks nice! Glad you're enjoying your father/son bonding sessions.