Gustav V 20 Ore Violet 1921 (Sweden)

Happy New Year guys,
A question that baffles me:
Why listed on Most Valuable Swedish Stamps the Gustav V, 20 ore 1921 (Violet) is valued at $3,500 US but on Stamp World the exact stamp is selling for $0.10 US ?
There is no special watermark or misprint indicated as the reason for its' rarity, just maybe a few among the other denominations.
I really need clarity on this.
Ian

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Where was the listing you refer to?

My 2006 Scott classic specialized lists a 20o, violet, at $4,500. The Scott catalog # is 189A. The normal Gustav issues were unwatermarked, with minimal CV. The expensive one has a wavy line watermark (wmk 181 in Scott). Not sure if this is listed in the regular Scott catalog, or just the classic specialized.

Ok. So the watermark could be the difference ? I would check my 15 ore Gustav for the watermark. If it is there then that eliminates the watermark as an issue.
Thanks everyone for responding.

Not seeing any Ws . So that could be it.

I'd say yes, that's probably it. I've checked hundreds of 20o's over the years, and I'm still looking.

hello, I apologize for bothering you, can someone help me and tell me if these 2 stamps are valuable or not? I can't figure it out and I have no one to turn to in my area

You can, always, check at "stampworld.com". There's a world stamp catalog. But, refering to your question, I'm afraid, the stamps shown, have minimal value.

Thank you for the quick answer, I looked but as , there are many variations and as I am not an expert in the field I did not know what to believe

Your Swedish 20o stamp would need a watermark in order to be the valuable variety. They are very rare. I don't think yours is the right shade to be a candidate, but the image is washed out. Just check for a watermark.

can you tell me how to look for the watermark?

Buna ziua @Dean_009
I am happy when another collector from my country registers on the website.
Welcome! Bine ai venit!
I put the used stamps face down on a black ceramic plate.
If it is not enough, I moisten them with water or look at them in the sunlight.
For gum stamps, instead of water (which dissolves the gum), I use a cleaning solution called NEOPHAL - I have a pipette with which I put a few drops on the stamp. It is recommended to do this operation in a well-ventilated room and away from any source of fire.

Multumesc mult, I will try to put it under a light source