It's actually a discount in that regard since most people would have to spend considerable time learning how to take that photo.
It's a perfectly good starting place for a price. And nowhere did he say that price wasn't negotiable.
It's similar to buying anything on the market - A toaster would cost hundreds of thousands of dollars to build from scratch (http://www.thetoasterproject.org/), but no one pays that much (not does any manufacturer expect that much) since no one is really going to build one from scratch.
The author's argument gets really weird at the end when he claims that if someone misappropriates the image, he would charge the cost of his camera, his laptop, his software - the whole shebang that went into it. It's a very strange way of computing the loss of value to him. The loss of value could be zero (if there was no buyer for that image in the first place - a lot of photographers take excellent images without anyone actually buying or wanting to buy them ever), or it could be many thousands of dollars if it is a piece of art that is highly valued. Basing the value on the cost of the equipment that went into producing it does not do justice to the image either way.
I also suspect that he would be happy to license uses of that photo for substantially less (though I'm VERY curious as to what that cost is, actually) to magazines and other people wanting to use the work on a single-use basis.
What many people with only a superficial understanding of economics don't seem to grasp is that the "perfect competition" ecosystem that is described in Econ 101 - in which goods are priced at cost - is an EMERGENT property of free trade.
Key word is emergent. The cost of a good is not enough justification for judgment of what someone out to pay for that good. When that good, labor, and all inputs of that good, and inputs of those inputs are priced fairly and freely, then such pricing tends to emerge. But saying "I paid $XX for a plane ticket and this equipment to produce this good so I deserve to be paid $XX for it" is Begging The Question. The inventive camera maker, or the bankrupt airline that sold you the plane ticket below cost, could be make the same argument of you. And the cheated, suicidal Foxconn employee who made the camera components could make the same argument. And so on.
The point is you can't force the pricing you want. Allow people to trade freely, and order emerges.