I think it is not overpriced, it's just a good stuffs making a increase in price, because that is how the businesses works. I think sometimes the price of something rise up or pump because of the demand and they need it that time that is why the price also increase, then after that time, the demand goes down, the same as the price.
You're right - price and demand are linked, but there's many other factors involved into making the value of a good. Although, as long as the demand rises and the offer stays the same, price will inevitably go up