Good question
A picture is worth a 1000 words and clears up many unknowns regarding condition, but not all. Exposure of your item to as broad a range of potential buyers is a must. I believe a fair price is what someone is willing to pay for something that they want. A collector will generally give you something fair, a dealer/reseller needs to turn a profit, hence 99% of the time a much lower price for you. You have done the research and know what this and similar cards have sold for. Combining your research with patience, exposure and an accurate scan w/ description should net you your asking price or close to it. Forgive me for stating the obvious, you can always go down in price if the card does not sell, you can't resell it higher once it is gone. Besides, no one wants the honor of being the person someone brags about making a "steal" on this or any other collecting/trading site.
My 2 cents worth
first off i want to say thank you to the bench community for helping me out with all my sometimes stupid questions as i try to get this selling for a profit thing right. so here is my question. i just bought a lot that included an ichiro/dice k/hideki triple threads triple gu card #/27. when i bought it the only on that had sold was #/36 and went for 31 but 2 days ago another one #/36 went for 67. my question is as a selller what would you do here to be fair? i was thinking of averaging them out and adding a little because mine is #/27 and not 36. the average is 49 plus a few for the numbered i was thinking like 52 or so. its just tough because not many have sold and ive never seen a couple items sell for such a huge difference in price. what would you do in this situation? i want to be as fair as possible to the buyers so im not going to ask for 70 but i also dont want to take 30 either.