No offense, but I've never understood the "give them more than what they're asking for thing". I figure that if they're in dire need enough, they'll take the time to maximize their profits and know the value of what they're selling. For many, this is a business and paying more than the asking hurts the bottom line.
Essentially, why should I feel guilty about the time and effort that I've invested in to knowing the value of an item?
There are times when someone passes away, like your last surviving parent. ...I know, sounds strange, like it couldn't ever happen, right? Well, all too often the kids (normally adults) will sell off everything quickly, or even have other people sell the belongings for them, as they can't may live very far away. It's all on a case-by-case basis. If the people are rude, obnoxious or otherwise, then hell no, I ain't giving them a break for nothing! But I can understand how easy it is for one person who knows very little of, say, coin values, antique or costume jewelry (or how to tell the difference), or even very old photographs from the 1800's to early 1900's. Old power tools (some are highly collectible!), old toys, figurines, glassware, etc, etc, etc. Even old, outdated clothing. I once went to an auction where there was a TON (or two!!) of really old, antique stuff of ALL sorts! Price tags still hanging from clothing, tools and outdoor gear that had never been used, antique jewelry, etc. We bought an old sprinkler from back when they were made AWESOMELY well for $1, new in box!! Bought it because my folks had just said how they wished they still made those older good sprinklers. So we sent it to them. They never opened the box thinking that it might be valuable some day - and some day I'm sure it will be, but....
Anyway, point is, some people don't have a clue about the value of things and, frankly, just don't have the time to research everything. So I know it's a stretch to the imagination for some folks, but if I see something for sale that I KNOW is worth many times more than they're asking, AND if the people have had some recent tragedy AND the people are friendly, then dang right I'll do right.
I know a little bit about coins now - not much for value, but enough to understand that even normal-looking coins can be worth much more than face value. I didn't understand that before joining Tnet....which was less than a year ago. Does that mean I was an idiot? A moron? A real dummy? Nope - just means that I was uneducated in the value of seemingly-everyday coins. Never had a clue that 450% and 90% silver halves and dollars were so valuable.
Another member here goes to one of his regular banks, where some of the tellers often set coins aside for him. They''ll say they want X-amount for them. But then he may offer more. WHY?!?!? ...If you don't get it now, you never will.
Again, this would not happen E-V-E-R-Y S-I-N-G-L-E T-I-M-E, but using the above criteria (and playing it by ear), it is very likely that I would offer a bit more if it seemed they were good folks who were simply uneducated in such matters and, frankly, had bigger things to worry about than researching everything at the sale.
I don't expect everyone to be this way - same way as I don't expect everyone to be polite and courteous when we go to town. Everyone is different, and I won't hold it against someone for having different ideals or values.