Premium to Spotify Family

[chiribibi]

Hi Spotify, I have a dude, I actually have a "Premium account" and I want to become a "Premium Family account", but I am suscribed just for Premium paying PEN 16.90, now, to have a Family account for 3 members costs PEN 33.90, I want to know if I have to pay PEN 33.90 else or if I have to pay just PEN 17.00(33.90-16.90=17), and I have another question, in my Premium account I just can dowload my playlists in three devices, I want to know if having a Family account I will be able to download my playlists in more than three devices.
Thanks
Franck del Águila Gómez