Indeed. Not outrageous at around £1,200 per year as I see it.
In one sense, I don't see that I've lost much given that I have no intention of getting rid of the car.
I only do 5 or 6k a year now, and it's not impossible to imagine that I might get another 3 or 4 years out of it. It would then be worth nothing, but the depreciation would have been £1k a year or less.
I had been buying cars at two years old, then changing them when they were four years old. I found that for me it was the best balance of costs versus hassle. (I needed something that I felt was fairly reliable as I used to work in a situation where I was on-call 24/7/365 to a site 15 miles away.)
I had an Escort that was coming up to change time when the Focus came out. I either had to keep the Escort until it had no value, or buy an almost new Focus. I chose the latter.
How many of those were new? And over what period of time? From what you have just said, it would seem that some of your cars have been supplied by others, which is not an option I've ever had. Had that been possible, I would have done it.
Chris