How much is a Biki pass?

Excuse me, could you please clarify the cost of a Biki pass for me? I'm interested in knowing the exact amount I would need to pay in order to acquire one. Additionally, is there a specific time frame or conditions that need to be met in order to purchase a Biki pass, or is it readily available for purchase at any time? I'm hoping to gather all the necessary information before making a decision. Thank you in advance for your assistance.