Sometimes people have second thoughts. Other times they just want to get a feel for what someone might pay for their gun.

Whatever their reason, they are free to do whatever they want and aren't obligated in any way to do anything they don't wish to.

Many people are turned off when they find out how much of a hassle it is to sell and export firearms across state lines, not to mention shipping costs.

It's perfectly acceptable to entertain offers for something. If someone accepts your offer then recieves a higher offer, who are you to feel that you're somehow entitled to it?

Man up your offer if you want it, it's buisness not a buddy system.

Simple as that.