As you have found, the damages can be severe...
But I think that there is a fourth cost as well.
Time. My time off is precious to me. I don't want to spend it on a problem. A blowout can ruin and end a trip. That is something that I can never get back.
Good point you make. Another reminder to everyone that RVs is to take an annual look at the spare for condition and inflation. We were fortunate that our spare was brand new, but I had not checked it since buying the 5th wheel 3 yrs ago. It was way underinflated, but useable until we could get 10-15 mi. down the road to get it properly inflated.