Is this a rare misprint?

Hello, I've just sorted through (literally) over 2000 5 pence coins. This one stood out as the milled edge seems to sit too low and half of the edge is still smooth. I didn't see this in any other of the coins. Is this valuable? I am unfortunately still ignorant on how a striking error effects the value of a coin.

https://en.numista.com/catalogue/pieces70547.html <-- This is the coin page that shows how it should be.

It certainly is an interesting and unusual error. Ive never seen that on any coin.
As always, value depends on finding a bidder.

It isn’t rare no, it’s a partial collar error