Look aeria, you're gonna make me cry. Do you wanna make a loyal fan cry? ;.;
Seriously, this game would make a great investment. It requires little upkeep as most of the game is player driven, and the it appeals to most of your market. The simplicity is easy for new gamers to start playing, while the skill needed to be good at it attracts veteran players. Since you can participate equally at any level, both casual and hardcore gamers would have their way.
As for income, Fantasy Earth Zero was set-up in a manner so that gambling (what you guys call loot boxes and tiered spenders) are easy to install and change-up. I knew a few people who spent a ton of money to get a sword that wasn't any better than my nooby axe I spent a few bucks on to upgrade it.
With all the games you guys have been putting up lately, I see no reason to not add an old classic to the mix. Hard, you might even pick up that niche filled with old rpg and final fantasy fans.