Not enough light on the 'horn' to see the detail so can't even begin to make an estimate.
Maybe try taking a pic in natural sunlight-without a reflection.
Don....
Before value can be estimated, the coin's grade needs to be determined.
The Red Book indicates these grade levels:
G-4: Horn does not show
VG-8: Horn worn nearly flat
F-12: Horn smooth but partially visible
VF-20: Much of horn visible
I don't think I need get into the higher grades.
Based on these, what do you grade your coin?
The RETAIL values for those ratings fall between about $8 and $115.
Don...
Here's a more detailed definition of VF-20 that some collectors use. Does this fit? Summary: Moderate to minor wear exists only on the highest parts of the design where a slight flatness is beginning to show. Although worn, the overall condition of the coin is pleasing and attractive. Obverse: The Indian's hair and cheek are noticeably flat but not lacking in detail. Partial details in both feathers are showing. Reverse: The hair on the buffalo's head is worn and the horn may be incomplete. The hair on the top of the Buffalo's shoulder has some detail.
If so, you can then go to Ebay and look up Completed Transactions of your coin to see current actual sales prices.
Don....
I would grade that as a Fine-15 details, maybe VF-20 if I saw it in person. It has been dug out of the ground, which severely decreases the value. The net grade would be about a Good-6, give or take a couple points. I see it being worth about $10-$20 max.