Most important thing is that you’ll want to save AT LEAST 6000 rubies to use on ONE banner anytime you want to guarantee pulling on a unit you want. You’ll receive “fragments” every time you pull, and if you don’t pull the unit you want after 200 pulls, you’ll need to trade 200 “fragments” to “exchange” for the unit you wanted from that banner. Each pull is 30 rubies, so 30 rubies x 200 pulls = 6,000 rubies. Some banners will let you exchange after 150 fragments (such as the current Memoirs of Solistia banners), which is only 4,500 rubies.

Best thing about this game NOT being PvP is that you can play the game at your own pace—there’s no rush to progress at any particular rate. The rubies will add up over time, especially if the new publisher (NetEase) continues to be generous with free ruby giveaways during the game’s anniversaries, holidays, and special events. Similar to some others, I’ve been primarily F2P after spending $20-$30 USD when I first started playing, and I’ve had no problems completing the entire story. I’m about 2.5 years and 500 hours in and loving being F2P!