Oh, man.
It is the way the market works.
Let's go to the apples example.
A farmer produces five apples this season and sells them to many merchants.
Seeing the demand for apples is going to increase beyond the a availability of apples this season, the merchants rise the price, because they can* and it is their job (they gambled buying them in the first place in order to potentially sell them later).
Sure next season the farmer will produce more and perhaps the apple fad will not be so strong, meaning the price will be reduced again, but the future is NOT today.
* If they sell it for a lower price, the product will be sold out when there is still people willing to buy it, if they rise the price less people will be willing to buy it, and if they keep rising the price there will be just enough people willing to buy it and the whole stock of product can be sold. If they sold it to cheap, many people that want it will not be able to have it (and they will be stupid and losing money), if they sold it to expensive it will just accumulate dust in some warehouse. The optimal free-market equilibrium dictates high prices for high demand and low supply, it is basic economics.