I think that real estate agents are also very tuned into the concept of value being fluid. That is, an item’s value is really whatever someone is actually willing to pay at a given time and place, and not some well-defined number that can’t be argued with (no matter what some “collectible price guides” would like to think). Haggling (or “making a counter-offer”) is a completely normal thing to do in both activities — though I’m glad to say that having someone offer more than the asking price is practically unheard of at yard sales. This price fluidity can be really great or really frustrating when you are dealing with secondhand items. Just like people might have a hard time accepting that their house isn’t going to sell for what they think it should, there are yard sale sellers who think that if something sold on eBay for a certain amount, their similar item should get the same price at their yard sale. On the other hand, when you find something that’s priced fairly to you, it’s a beautiful thing (even if the person next to you wouldn’t have paid half that much for it).
This is something that I've thought a fair amount about, and an attitude that I gradually adopted the more I bought things used. I didn't even realize that I'd developed this outlook until one of the first times that I took Josh yard saling. He was eying this statue of the head of Siddhartha. We had asked the price, and it was something like three bucks. Josh whispered to me, "Is it worth that?" I shrugged and replied, "I don't know. Is it worth that to you?"
That's really the point when you're at a yard sale. It's not about what the seller thinks it's worth or how much he paid for it in the first place, it's about what you're willing to pay for it. Would you rather have the statue or the x dollars? For what value of x does that answer change? Can you get the seller to agree to that value? Sometimes, you can't. Their value system is too different from yours.
Since there is a disconnect between your value system and the seller's, this means you have to let some things pass. That's hard to do sometimes, but I promise I've regretted buying something much more frequently than I've regretted not buying an item. Learning to not buy something seems to be a useful skill in other areas, too, one that is especially useful now that my value system is so skewed to expect yard sale prices on everything.
If you were curious, he did buy the statue. I think he might have negotiated the price down, though. He's a quick learner.