Advice on selling a ring

I’m hoping for some advice. I have a very nice ring that was made
for my grandmother years ago. Its quite large and not something I
would wear. Its rather strange, but I’ve never tried to sell a piece
of jewelry that I haven’t made, so I have no idea what the best way
to do that might be. Are there any rules of thumb that I should know
when privately selling a piece of fine jewelry? I want the best price
I can get obviously, ring sale new roof (desperately needed!). Any
suggestions on where to place an add? I thought of eBay, Etsy, etc…
Does a jewelry store sell on commission? I did have a formal
appraisal done which I assume should be made available to the
potential buyer. Any advice would be much appreciated.

Leslie S.