Having sold the boat ( sob, sob

) I have set about getting rid of some of the large stock of boaty bits that remain. Outboards and charts and books and rope have all gone but last week was the turn of some new still in packaging buoyancy aids and some wooden oars. All offered via Gumtree.
Leaving aside how I managed to aquire 6 new unused buoyancy aids in various sizes ( I havent a clue) , I advertised them at what I thought were sensible prices bearing in mind they were at least 20 years old. Chap came and bought two. How much? £12. Here is £20.
Much the same with the oars which were £10 and again I was given a £20.
Initial reaction was pleasure at their generosity. Then I got to wondering. Am I so out of date that what I think is a sensible price is silly low? Is a £20 note now just loose change when I see it as serious money? Am I in a 1950s time warp value wise. Could well be since I was staggered to read that it is possible, never mind sensible, to pay JLR £200k for a new Range Rover! They ought to be £30k!
Am I completely out of touch.