I don't know if it's fair to compare mounts in WoW to a monster in Evolve. WoW has hundreds of different mounts to collect which are mostly just cosmetic anyway. For example, buying a $15 mount won't make you run or fly faster.

The rarest and most coveted mounts in the game are the ones you have to earn by playing the game and doing things like defeating a raid on the hardest difficulty or getting it from a boss with less than a 1% drop rate...

WoW has PLENTY of content that makes the price worth it. If you compare the amount of content in WoW to the amount of content in Destiny, WoW leaves Destiny completely in the dust in terms of economic value.

Evolve doesn't have the luxury of having so much content, therefore any new content they release is going to be much more important to their player base than a single new mount in WoW. The new monster gives you a new way to play the game, it's not just cosmetic and it sounds like the game desperately needs more content to keep players invested in the game. If the game fails to keep people interested the entire game will suffer due to a plummeting population.

Since there's only 3 monsters in the game and half of the game consists of choosing a monster to use in multiplayer, having that 4th monster locked behind a $15 pay wall doesn't seem fair to me, especially when you've payed full price for a AAA title.

Is WoW expensive? Yeah, you could definitely argue that. Is it worth it? I'd say it's pretty easy to justify the cost considering the sheer amount of content in the game.

With Evolve you're buying the game and then if you want to have all the other content you need to buy the Season Pass separately, which anyone serious about buying the game is going to do since playing the same characters over and over again will eventually get boring.

I applaud 2K for releasing new maps for free so that players aren't forced to pay to continue playing with their friends, whoever I still feel like I'd be missing out on important content if I was watching other players run around using their cool abilities that I didn't have access to.

Personally I love the idea of the game and it looks really good, but I can't see how they're charging full price for a game that's essentially multiplayer only.