Error on this 'collectable proof' ? Is it worth more/less? 0

[drewspuppet]

Purchased a lot of 4 coins, low sequential serial numbers original mint packaging likely never opened on all. 

 

This coin looks like maybe a laquer failure if they do that to these, due to the opal encasement? You see the spot, then if you look the lettering The Monkey below it is strange in the top of font and some milky where should be mirrored finish. 

 

Are errors on these types of collectables valuable? 

[drewspuppet]

..

[Greenstang]

Not an error and not valuable. Most collectors of proof coins would consider milk spots and staining as damage and detract from the value of the coin.

[drewspuppet]

Thank you for they reply. I wanted to ask those who know just to make sure. That was my thought also. 

[VKurtB]

It’s just sick that a milk spot as nasty as that has already shown up on a four year old coin. It’s environmental in my opinion. I have been spared the ravages of milk spotting somehow. Must be clean living. Maybe not.