I used a VPN to sign up for YT Premium in a cheap country, using my regular credit card, about 6 months ago. Since then, I haven't used VPN once. I've been accessing the account from all my devices, including an Apple TV, using my regular internet, and they don't seem to care.
I've also ditched Spotify and am using YT Music, which is included.
For this, I am paying about $1.50 per month, and I consider it totally worth it. Also, I'm pretty sure what I'm doing is completely legal.
Annoyingly they've started to come down hard on this method by cancelling subscriptions that signed up to a cheaper country using a VPN.

YouTube is canceling Premium subscriptions bought using spoofed locations
The VPN workaround might not work anymore.
