Value of a point

I have been studying several economic blogs now, covering everything from Trade Barking to using professions profitably, and Crafting vs. Gathering. AHtrader made a point about crafting items that are not worth their mats. It seems the vast majority of recipes do this exact thing. Buy or farm 100G worth of mats to create an item that might sell for 80.

My question is this: Assuming one's skill is not at maximum, how much is a point worth? Granted, a crafter can always sit in a random capital and Bark "FREE UR MATS," but for that to work, said tradesman has to actually attract customers. As a customer myself, if I need to scour the AH for the mats, I might as well just get the product the trader advertises. After all, it is usually cheaper that way. And as a craftsman, I generally place my wares (In my case, Enchant Scrolls. Other characters have different professions, too.) in the AH, and hence I do not worry about adverting in Trade. After all, time not barking is time spent either farming greens for DE, or just plain talking or *gasp* PLAYING.