You might get better responses in the Japan forum (Or maybe the JAL / ANA forums) as there are more Japan citizens/residents there who probably would be able to give more localized advice.

For instance, the deal sounds terrible (to me) because my country has credit cards that offer full priority pass (unlimited visits for cardholder + guest) as standard benefit. But this data point is useless to you because your country possibly / probably may not have those sorts of cards available.