No, that's called supply and demand. Ecom-101. The value of a product is what someone is willing to pay for it.
No, the value of a product is it's worth as determined by the market, not "what someone is willing to pay for it". If I sell you a dog turd for $1500, it doesn't mean that a dog turd's value is $1500. It just means that you got ripped off. It's also worth noting a "market value" doesn't imply an understanding of "actual value". "Market value" can be influenced by a number of factors not relevant to it's "actual value". A good salesman can sell you a product for a larger amount than a poor salesman. The "actual value" of the product doesn't change.
You should probably try showing up for that Econ class.
You're right. Selling a dog turd for $1500.00 doesn't necessarily establish it's value. It could be the result of an aberrant transaction.
If you manage to sell 70 million dog turds at $1500.00 a piece in six months, you might be on to something though. At that point, does it really matter what you think the "value" is and what that entry level Econ class taught you?