how much is the monthly subscription (Final Fantasy 14: A Realm Reborn)

30 days $14.99
90 days $13.99
180 days $12.99

The game appeared in steam and there are subscription costs 289 p

Orvyn
I can't find where steam is a subscription to pay.)

Kind Ram
Go to Mog Station and where to pay the normal subscription, choose - Steam payment" or something like that, you will be redirected to your ACC on steam.