A Roadster with decent spec was £41K in 2005.
Now I think it's about £20k more for a similar spec.
So 30% plus rise in twelve years. Given that most mileages are tiny there's no wonder that residuals are good.
I would have to spend another £25k to trade my Roadster for a new one. Why would I do that.
The risk is that new Morgans may pass the sellable barrier but they haven't done so yet.