Wow 49 years that's amazing 👌. 

1 feed auger turned 49 last November, the other reached that age a few weeks ago LOL.💪💪💪   I use very few flex augers.  Just from commodity bins to the mixer for shorts ( 100 t annually) and soyameal (250 t annually).   Corn is a rigid auger.  Make my own feed on farm.      My finisher barn is a chain disk system.  I replaced the drive unit once, it was about 20 yrs old at the time, that was about 10 years ago.  Did chain inside in 2014, as I added an addition to the barn, and didnt want a mix of old and new chain.   Pipes are the biggest wear item.  Used galvanized last time(2020 ish), but likely go stainless next time.

That's why I still use regular a19 ones 😆.  I had a cross auger motor fail a few weeks ago. I got old one out before crew arrived. Took two of us to push augar back in while third fastened it down. How long do they last for you typically.   I rebuilt an emergency spare again and keep it on shelf. All wired ready to go. One that failed was 9 years in service 

Hog slat in Mitchell told me one time they have a customer they go to, even if its just to replace a fluorescent light tube in a barn

Not sure about that one.  I never made huge profits but I keep re investing back in to gain efficiency's and to live another day. I make enough to pay my bills that's about it. Be lucky if I retire by 65. I was told by a few contractors not many farmers like me left now. Most don't do any pm maintaince and just call when stuff breaks 😆.