I thought so too, but this is what she then says…
"Aquinas asks first whether it is lawful to sell a thing for more than its worth. This might strike us as odd if we think that things don’t have any inherent value outside of the value the market assigns. Aquinas thinks the value of something depends on their usefulness to a person and that just exchange serves both parties equally. Now, if the thing being exchanged is faulty, either because it is broken or because it is not worth as much as may be claimed or because it is of lower quality than may appear, the sale or exchange of that thing is unlawful. Aquinas says that in all these cases, “not only is the man guilty of a fraudulent sale, but he is also bound to restitution.” Even if the person selling the faulty good is ignorant of the fault, he is still bound to restitution. This ensures that the common good is protected by restoring equality where inequality exists. This means that houses that were sold for more than they were worth were fraudulent sales, even if the real estate agents and lenders and home owners didn’t know that the homes they were selling were overvalued. It also means that the people who profited on these sales are bound to restitution. Banks and companies that profited off of mortgage-backed securities that were bought and sold for more than they were worth rightfully should pay to restore equality.
But somebody may respond that it is perfectly reasonable to sell something like a home for more than it is worth, if a buyer exists who will pay the price. Aquinas disagrees. First, he distinguishes between two types of exchange. The first is natural, as when one thing is exchanged for another, or for money equal to the value of the good exchanged. The second type of exchange is the exchange of money for money or money for a commodity not on account of the necessities of life, but rather for profit. This kind of exchange “is justly deserving of blame, because considered in itself, it satisfies the greed for gain, which knows no limit and tends to infinity” (Q. 77, art. 4).