Another way to look at it, the knowledge you have gained in the process.
The only knowledge I learned which has turned out to be priceless is----DON'T DO MECHANICAL WORK AT HOME FOR FRIENDS!
99% of the time it will somehow turn around and bite you in the butt. Case in point, a friend's ancient tractor quit while he was working up his arena. The IP had the same rubber pump drive as the old 855 cu.in. Cummins and it had sheared, no big deal. I played semi-stupid but another friend jumped at the chance to fix it. Turned out the further he went the further he had to go. He ended up with the engine completely torn down pretty much out in the open, then the wonderful Wyoming winter came and he had that mess to look forward to come springtime.
Heavy truck and diesel mechanic (thankfully retired after 30+ yrs)
'91 F-250 SC 4X4, 5spd. ATS Turbo, 3:55 diff.