If it is homework, I bet he gets the best grade in class. If he actually reads all the cases and discussion, he will know the "answer" as well as anyone. Since the answer is not the point of most homework of this type, but learning how to do original research, the grade should be fail.
As a final point (although I alluded to it earlier), valuation is harder than you might think. It's not a matter of a number unless we have an arm's length sale which fairly establishes it. (Determining if the sale fairly establishes it is a matter of facts and circumstances.) Otherwise, we have a potential argument. This valuation problem comes up in a lot of areas. Say we have an estate and get a qualified appraisal valuing a property to get a step up. Then, we sell the property for a MUCH higher or lower price within a year. If a large estate and the amount is much higher, do we have a capital gain or a higher estate tax? (A substantive difference in tax owed.)
How about putting a minority interest of an S-corp in an FLP or trust in order to reduce the estate. (For valid business purposes of course.) We don't just take the book value of the assets (including goodwill) we try to create an argument to have the "value" be as low as possible, thus allowing us to get as much out of the estate as possible without paying the gift tax. The value is argued to be less because of the lesser ability to alienate the minority interest. Who would want to buy something that is hard to sell? The fact it would be hard to sell makes it worth less. Also, being a minority interest, the lack of control puts the value less too. If the majority interest can determine to put profit back into the business rather than make a distribution, the minority could have a problem of having to pay taxes without having any money to do so. Again, reducing it's "value". (There are other things we could argue here too.)
However, it's the same thing. Same stuff, same percentage ownership, same rights as was held before. Yet, for actual, real and subjective reasons, the fair market value is less. It's not a different problem just because we don't have an S-corp dealer who put a price tag on the interest.
We don't really care what the store, or dealer, or artist, or carpenter or whatever, claims what something is worth or what it should sell for. If there are a lot of sales at a certain price, that would certainly be part of the argument, but, there are other factors involved. No sale is exactly the same as another. We could have a billion sales of SUVs at $1,000 each on one day, the next Iran gets the Bomb and gas prices go up to $10 a gallon the next. In a very real way, the SUVs are suddenly worth a LOT less.
That's why the Supreme Court is right on how to determine the value of something. That, and the fact they don't want to argue every sale, is why the IRS agrees if you have a true arm's length sale. Are they going to start challenging all stock sales by saying it was actually worth less when you bought it or you should have gotten more when you sold it?