Man! As hard as I worked to find an axe like that, to think you want to sell it. Come on! Of course their is a market, if not sites like this would not exist. I understand, this stuff is not as valuable to others as it is to me, but you stumbled on to a fine piece of pre-history. Not another just like it in the world. Why not keep it and pass it on?
One more thing. I hate to even say this but, I think $500.00 is about tops for it. In another thousand years it will probably double. Personally, I'd keep it until then! Money is what causes so many people to have to secretly hunt artifacts. I wish the two never met.
Please don't sell it. Something like that should stay with your family and be a story to tell. Mine is a center piece in my living room and one of my proudest finds. Couldnt imagine some one besides my kids ever owning it.
Do with it as you wish but the market is down rite now on artifacts. Wait a couple of yrs and maybe get more for it. Although yours looks like a very nice one. Probably 400 to 500 for that one. 2 yrs from now if the market turns back around 800. Your choice