I think point worth has changed since I made this (its old..almost 2 years) as I recall doing the math on at least something haha. At the time I think things like the commission widget and the premium content downloads werent implemented yet. Looking currently I can buy 400 points for $5, that's 1 point = 1.25 cents to purchase them. To convert acquired points through premium content downloads it looks like you're right if taken out as money it is 1 to 1. If I wanted to convert my 'profits' or whatever back in to points though I then lose out on a chunk as it goes back to 1.25 cents per point.
So.. person 1: 400 points payed for (-$5) 400 point commission or content payed for to person 2 (-400 points)
person 2 : receives profit (+400 points) two outcomes now -convert profit to $ (+$5) or -convert profit to points to pay for commission or content (+320 points)
So the system is a little different now that you can actually convert points -back- in to money . Either way though this stamp was more about appreciating the fact that they're just not worth much on an individual basis. Pennies in a jar are still pennies and not dollars.