That payment method is no longer available.
Valve decided to remove the possibility of payment via Bitcoin on their digital sales platform, Steam, so if you wanted to spend your new found millions on games it will prove hard.
The company detailed the decision in a blog post citing the volatility of the currency and very high processing fees as the reason behind this decision.
“The value of Bitcoin is only guaranteed for a certain period of time so if the transaction doesn’t complete within that window of time, then the amount of Bitcoin needed to cover the transaction can change. The amount it can change has been increasing recently to a point where it can be significantly different.”
Due to that, the company either returned the difference if the customer was overcharged or demanded the same in case of undercharging. In both cases, the Bitcoin network charged transaction fees two times.