But yes, it would not be abusive if there is no way to pay. If the mechanic exists solely for gameplay reasons, rather than for manipulating the player, it's not taking advantage of anyone.
>If the mechanic exists solely for gameplay reasons, rather than for manipulating the player, it's not taking advantage of anyone.
If a person spends 100 hours in a game which requires ridiculous grind that's less evil than if they spend 5 hours in a game and spend $2 to unlock extra turns sooner than just waiting while having equal amounts of enjoyment?
Time is money. You may not value your own time but I and others do. Even in "pure" experiences if elements of play are there for gameplay reasons (every game having different goals) it can cost a person a lot of money just by playing it for a long time.
Imagine a game where you build a village. You need gold to build something. The game gives you X gold every 5 minutes, and you can pay to get more. Sounds reasonable, right? Except that there is no gameplay reason for you to wait 5 minutes to get more gold. They could just as well give you more every 30 seconds and the gameplay would became 10 times faster and more enjoyable.
If there is no option to pay with money, there would not be any need to pay with time either.