Capitalism and Stealing

I have previously admitted here my fondness for advice columns. A while ago I read a letter from a teen whose friends got arrested for shoplifting, who wanted advice on how to persuade her parents to let her see them again. She said that " All they did was swipe a few things from a company that makes millions of dollars by overcharging customers for their stuff" as if the company's profits make it ok to steal from them. There seems to be a fundamental misunderstanding about capitalism going around. How capitalism works is:
I have something I want to sell, and I set the price. If you think the item is worth the price, you buy it, and if you think the thing is not worth the price I've set, you don't buy it. Yes, there can be haggling in capitalism, and the seller can change the price in response to the market, but the fundamental principle is that everyone buys and sells at prices they find acceptable.
This company making "millions" is selling there product at prices their customers are willing to pay. They don't somehow not deserve the money they get for their goods or services because someone thinks the company could charge less.
I'll put it another way: at my job, I'm compensated at an hourly rate that is above minimum wage. There are some other positions at my company that get paid less than I do per hour. That does not make it ok for a fellow employee earning a lower rate to steal from me because I'm "overcharging" for my time.
Your gut may tell you "Hey! That's different!"- but why? Because I'm an individual rather than a faceless corporation? Corporations are made up of individuals whose wages are paid out of the corporation's earnings. Maybe you think it's different because my time is being spent in a more valuable way than the hypothetical other employee and I am earning my higher hourly rate; a store that successfully sells t-shirts at three times the price of the shop next door similarly is creating more valuable shirts and earning their higher price. (A shirt's value, here, is determined by customers and demonstrated by what they are willing to pay for the different stores' shirts, not based on any intrinsic qualities of the shirt; identical shirts sold by the two stores for different prices would have different values) Just because you think customers are overvaluing a store's products, you aren't suddenly exempt you from the market and entitled to a freebie.
My point is: "they have so much"/"they have more than I do" is not a justification for stealing, it is a facet of the free market. If more people learned that as kids, we'd have fewer adults wandering around who think it's ok to steal from and cheat businesses and the government.