The condition level, e.g. 1 2 3 or 4 is very important to understanding the values.
I think there are very few condition 1 cars around. I think i have probably only seen one or two ever. They are trailer queens and would not be driven and hence their high value to get them there. I think any good restoration workshop would be wanting $USD200-350k to do a restoration to that level, and that does not include the initial purchase of the car.
Most cars are in the three and four level unless they have had a bare metal restoration in the last ten years and have then been well kept.
I think lots think their cars are at level 2 but the reality is that they have not won nor would win a concourse or similar and thus probably don’t make it to L2.
I also think that the 230 and 250 SL’s are under rated a bit like the 300sl Roadster was a few years back and will eventually level up with the 280SL’s and thus a better investment in the longer term.
Just my opinion. and I may have to wait ten years to say I told you so.
Garry