Puffin forgeries exist:
https://en.wikipedia.org/wiki/Coins_of_Lundy
These are the cheaper values
3000 were minted proof in a box (called 'fantasy set)
They are replica's of the 1929 coins. These values are higher
Only 25 made of gold
This one has scratches on the coins (cleaned)
https://timelineauctions.com/lot/lundy-island-1929-and-1965-coin-sets-6-/24779/
The fair prices can be found in auction houses, not on ebay.
On ebay the values are much to high. They all say it is scarce and in top condition.
Just watch how long these item stay on ebay. That means the asking value is much to high.