This isn't reality, it's a game.
It doesn't have anything to do with grieving or not being willing to pay a certain amount, either. For example, you can be willing to pay 10m for an item, but if you see one for 5m, you're obviously going to want to buy that one instead. Just because you would rather buy the 5m item doesn't mean you are not willing to pay 10m. Not everyone is malicious or thinks about just dropping out of something when they don't get their way. Most people are pretty mature about it. If you were able to get the cheaper one, then you could cancel your bid on the 10m one, and if you didn't get the cheaper one, you were going to spend 10m anyway, so chances are you wouldn't have an issue keeping the bid up.
I'm 99% certain anyone buying anything would rather have the cheaper of the two for sale, if you happen to be the one to notice the cheaper item, and are able to get it before someone else does, that would be nice.