In WoW for example I only pay 15 USD a month, but sometimes I have enough gold to just pay someone else to pay my game time for me. Once every 2-3 years is a 50 dollar expansion (if didn't get collectors edition).
Everquest 2 is only 15 a month, more expensive than WoW with all its expansions, but still not too bad
EVE Online is very free, and only 15 dollars a month if want to unlock more stuff. Plus free expansions
star citizen however, people are spending 10s of thousands, a couple even 100+ thousand dollars on the game. You can buy ships worth 100s and 1000s of dollars.
A lot of people in the past complained about subscription MMOs being too expensive. But now we have star citizen where its easy to pay for so much for ships. And yes at release you can unlock them for free...but its not even close to release so that isn't going to take into account cause I'm talking about NOW. And NOW if you want to buy ships and stuff, you must pay so much money to get them.
Its actually a lot more expensive than any subscription MMO I've played, if you want to unlock all the content inside the game. I dont even spend 1000 a year on WoW, yet one ship in Star Citizen can cost more than that.
My Skyrim, Fallout 4, Starbound and WoW + other game mods at MODDB: