Parents used to pay with Game Cards and I eventually bought my own. When WoW Tokens came out in 2015 (according to wowpedia, I can't remember) I started paying with gold and have done so since and will do until the end of WoW. I convert it to balance to get longer sub slightly cheaper, but promotional mounts since The Dreadwake are not longer included like that so you have to buy them individually if paying like that.
I also set up a US Account last year now apparently, my parents paid initially due to concerns which I paid them back for. I'm unsubbed from that account right now but have considered resubbing, and have enough gold to buy a few tokens. Unfortunately due to EU/US restrictions I cannot get Blizzard Balance for US and can only get 30 days of Game Time directly.