It's mega cheap if you use a VPN in somewhere third-world like India and sign up with a card that doesn't charge forex fees. You can then disable the VPN permanently.

I pay like 130 rupees a month (£1.30 GBP) for it. Worth it just for no ads on my phone and background playback.

Only 'gripe' is that YouTube Music sometimes pops up with random Bollywood/Indian tunes but once you train the alogrithm they disappear too (although I use Spotify anyway so it doesn't really matter).