The way I see it is, hobbies cost money. I'm a crafter, and I also play video games. As a crafter, I've spent so much money on clay, paint, resin, paper, ink... It's added up to so much more than $120 a year, I don't even want to think about it.
And then even when there are Steam sales, I've purchased so many games... Then there's the Big Releases for me, which are $50 or $60 per game.
As long as you're having fun and you continue to enjoy yourself, the cost of the sub is worth it. There are hobbies out there that are much more costly per year.