How do we actually calculate components cost? In the books there is always the name of the ritual, the price in the market, and the component cost. Is this a fixed price? I usually like to have all kinds of volatility in the currency and have something with fixed price in all the content kind of sucks. Is there a way to change the price without making the players pissed about it?
The price listed in a ritual's description is indeed the cost of the components that ritual requires. In fact, that's how the cost of every purchasable thing works in Dungeons and Dragons Fourth Edition: The listed price is the price. Fourth Edition D&D does not have rules for currency volatility.
As a GM, you are free to introduce house rules that simulate fluctuations of supply and demand, or to simply alter the prices of particular goods and services (including ritual components) up and down as you please... But be aware that 4e depends heavily on players having certain strengths and types of magic items for balance; If your altering the value of goods and services results in players being under- or over-equipped for their level, the finely-tuned combat mechanics of 4e will slowly start to break down. The problem will be small (possibly unnoticeable) to start with, but will rapidly grow to game-breaking levels if uncontrolled.
If you want to avoid enraging your players when introducing such house rules, you should explain to them that you understand the potential pitfalls, and also explain your plan to offset or avoid the those pitfalls. Such plans typically involve giving your players more or less treasure to compensate for the amount they're able to spend or save, or giving players bonuses and penalties in combat to make up for the difference between the gear they have and they gear they 'should' have at their level. (Yes, such compensation and correction does render your changes to the price of goods and services essentially meaningless. Predictable loot/bonus progression is an important feature of 4e's combat balance.)
Honestly, if fiddling with the economy is something you want to do, you might be better off playing a game with more support for it. Perhaps a trade-focused game like Ryuutama or Traveller, or simply a game where Wealth-By-Level isn't as important, like pre-third-edition Dungeons and Dragons or a retroclone like Adventurer Conquerer King.