If that's not the case and you really would only part with the pie for that high of a price, and no other pie will do for the child, then what is there to complain about? How much do you think it costs to buy a pie made by, say, Gordon Ramsay? Feel free to replace with someone who is actually a good chef and not just a famous one if I made a poor choice.
To me it is like asking should we allow animals to kill each other. Not only can we not really stop it, even if we could it would kill any carnivores.
Suppose I have a store card for a grocery store chain. If this grocery store sells my data to a health insurance company and the insurance company increases my premium based on my food purchasing habits, do you think it is fair? I am under the reasonable assumption that my purchase history is for the grocery chain only and in return for that data, I get some discounts on my purchases.
There was a case a while ago where a forum sold their users posts to a drug company. The forum members didn't expect that. Do you think it is fair?
In both examples above, the companies are most likely acting legally (After all, who reads 20 pages of legal crap before signing up for a forum) That doesn't mean it is the right thing to do.