Going to post this along with another that may have been kept together at one time either via string or on a necklace. How much value is lost because of the holes? I've read anywhere from 75% and up.
I think it really depends on the scarcity of the coin. I collect holed coins and generally consider a coin to go down 1 to 4 grades based on the size and location of the hole. That's just me though. There is no hard fast rule for grading holed coins that I am aware of.
1850-O is a little bit better of a date. I damaged maybe a $50.00 coin in fine condition. Holed, maybe half that would be my best estimate. However there are those out there that collect holed coins so you may do better.
Thanks for the input. I kind of rushed with these pics but will get them out for better pictures and put into holders.
If you have the right coin, with the right date, many collectors will pay fair money to fill a hole in their collection, but generally half or less than one without a hole.
Honestly, the coin shown looks to have more problems than the hole. Not too many folks collecting these by date anyway. There might be a buyer for it, but I think a lot would pass over it at $15. JMO