Yard sale sellers and 'pickers' should both play by the rules

As spring arrives, yard sale season can't be far behind. It's time for some people to clear out their unwanted "stuff" and others to go searching for bargains.
Several years ago, I wrote about my son-in-law finding a classic old fan made by Diehl at a yard sale in Somerville, Mass. He paid the owner 25 cents, took the fan home, cleaned it and fixed the motor. Years later, he sold the fan on eBay for $150.
My son-on-law had no idea what the fan was worth when he bought it; he just liked the look of it and figured a quarter was not too much to spend. Had he known the device was actually worth 600 times what he paid, was he obligated to tell the seller she'd woefully underpriced it?
A similar question arrived in my email this week from D.A., a reader in Ohio: "Occasionally, I come across a story about someone who found a treasure at a garage sale," D.A. writes. "If the person who's put an item up for sale doesn't have a clue as to the actual value, but the buyer knows it at a glance, what's the right thing (for the buyer) to do?"
For D.A., not saying something when you know an item is worth far more than what is being asked constitutes "stealing that treasure." It makes no difference, in his mind, if the seller is a child or adult, destitute or a millionaire.
My stance on yard sales remains the same as it's always been. The seller should try to get as much as possible for all items on sale, and the buyer should try to pay as little as possible. Generally, the seller and buyer meet somewhere in between.
Seasoned yard sale hunters have all sorts of bargain-hunting techniques. Some get to sales early in hopes of having first pick of the best items. Others like to wait until the sale is winding down and the seller might be willing to negotiate on price.
On television shows like American Pickers , buyers occasionally offer a few dollars more for an item than what a seller is asking. However, the responsibility of making sure the seller knows the real value of sale items doesn't fall on the buyer.
With easy access to online auction sites and other databases, it's simple enough for sellers to research what their items might have sold for elsewhere. Those concerned about underpricing should do the research.
If a seller asks a buyer if he or she knows what an item is worth, the buyer shouldn't lie. However, it's not a lie to simply suggest a price.
When it comes to yard sales, the right thing is to play by the rules. Sellers should try to get as much as they can, but price their merchandise well if their true objective is to sell everything. And buyers should go looking with a clear conscience for the best bargains they can find. 
Jeffrey L. Seglin, author of  The Right Thing: Conscience, Profit and Personal Responsibility in Today's Business and The Good, the Bad, and Your Business: Choosing Right When Ethical Dilemmas Pull You Apart, is a lecturer in public policy and director of the communications program at  Harvard's Kennedy School . 
Follow him on Twitter: @jseglin 
Do you have ethical questions that you need answered? Send them to rightthing@comcast.net. 
(c) 2014 JEFFREY L. SEGLIN. Distributed by TRIBUNE CONTENT AGENCY, LLC.