Purchasing items online with a credit card is as safe as doing so with PayPal. It is also much safer for the customer if your card details are not saved, so SE are actually doing you a favour by not saving your information. Yes, it's a pain having to go get your card each time, but pretty much every safeguard in life requires you to spend a little extra time making sure you're safe.

As other posters have said, you can also use Paypal to buy Crysta. If you select to buy Crysta, the amounts and prices are detailed.

Having read your replies, however, and seen firsthand your rudeness to people trying to help you, I must say I am hoping you decide this isn't the right game for you.