Putting someone all in vs. Putting them almost all in

[octop]

Over the last few months I've noticed that people are more willing to call a big bet if it does not put them all in (leave them a dollar on a 89 dollar bet) if they have a marginal hand. At first I thought this couldnt really matter much, but the more experience I get the more I am sure it does. I have even go so far as to bet more than somebody has if Id really prefer they not call (if its heads up) and betting a drop less than they have if I want the call (this ofcourse is against players who don't pick up on this, against a thinking player that dollar will not matter anyway)
I have a BBA in marketing and I was truly amazed at what a difference it makes when something is priced at $99.99 instead of $100, as either way I would think of it as 100 dollars.In general I am amazed at the stupidity of the average person so I am really curious if anybody has noticed this behavior in HoldEm. Thoughts?