An odd quirk of the non-subscription business model is that generosity can make paying for the product less attractive. The more stuff you give away for free, the less stuff you have left to sell people.
Case in point, Marvel Heroes has possibly the most generous model I've seen in a recent online game. All the content in the game is free, there's a decent selection of free starting heroes (see Yngwe's guide for details), the developers have repeatedly cut prices on the paid heroes, and changes since the game's launch allow players to unlock all of the playable heroes through gameplay.
I've gotten way more mileage and enjoyment out of an optional $20 unlock purchase for this game than I did out of the $60 copy of Diablo III that I paid for as part of WoW's annual pass deal. It feels ungrateful to complain about whatever prices they want to charge for whatever else they want to. But when I look at what they're selling I can't help but look at the prices and feel that the benefit of paying is lower than the benefit of paying in other products that have less generous models.
The purely optional cosmetic costumes are pricey (comparable to League of Legends - in both titles, these cosmetics cost significantly more than the characters who can use them). There are storage issues - in particular caused by the dozen different types of relics - that you can alleviate with modest amounts of real money. Like most other games, the cash store currency is only sold in $5 increments and almost nothing is on sale for even amounts - they're actually adding a free 250G grant to all accounts this week which is just below the price of the lowest unlock (crafting storage) that offers any real in-game benefit. Overall, the prices are comparatively low, but so is the benefit of paying them.
As multiple commenters pointed out last week, players who are not paying can still contribute significant value to the game's community. Meanwhile, freeloader or not, you cannot sell anything in the future to people who aren't playing the game at all. I just find it all counter-intuitive coming out of a subscription era, when purchasing decisions were strictly business - the product either was or was not worth continuing to play and you paid or did not accordingly. Knowing that something is for the most part optional and paying for it anyway to support the product? Strange new world we're living in.