I had a whole fleet of buses. My cheapest tow for about 4 miles that I was able to schedule for a convenient time for the tow truck operator (from my bus barn/shop to the International dealer) ran me about $350. On that one he picked it up from the rear so he didn't have to chamber the air brakes or disconnect the drive shaft. My most expensive, middle of the night emergency tow from the side of the road where we broke down back to our barn about 12 miles away was $1300. Both of those were 5 years ago before all the inflation.
I got a quote once to tow a bus about 130 miles from a small little town where we broke down back to our barn that came in at just over $3k. I paid my mechanic to take a road trip with me instead and we duct tape and bailing wired that engine back together and spent 5 hours limping her home to our barn to properly repair instead.
Long story short, big rig tows are expensive, much more than a scheduled transport, especially if its an emergency situation. If you can schedule out or tell the tow operator to come get it at their convenience sometimes you can save a few bucks. For my non-business personal skoolie though I'm going to carry Coachnet...