You will definitely advance quicker if you are prepared to pay some actual money. It is very good that the game is not pay2win – it is absolutely possible to go through the entire game in reasonable time without spending a single dollar.
That said, many people think it is worth to pay money. Best worth is the monthly VIP, where you will get some 1 500 crystals for a couple of dollar. If you choose to buy additional crystals, you will attain VIP 2, VIP 3 etc, with some extra perks.