Anyone with insights on how these compagnies design their micro transactions prices? I am very curious to know how they decide on these specific numbers.
But having been around the webgames block a few times, I think their microtransaction system is very flawed. It seems to want to milk the maximum amount from people who pay, instead of making it low enough to maximise the number of people who would see the system as fair enough and cheap enough to pay for. (In other words targeting the mainstream players instead of a very select few.)
What I would have done is something like this :
1$ for a full refill
5$ for a package of 7 refills
30$ a package of 50 refills + a permanent increase to maximum action points storage permanently from 20 to 30 and for all your future playthroughs (that will let people sleep a full night without wasting points, and significantly speed up progression for those who want to finish the game in a couple of days, AND make things smoother for those who want to replay it with a different class and so on, + a goal of 30$ per person is pretty good for short / story driven web game)
The game seems to last around a week to 2 weeks+ playing totally free, depending on the efficiency of the player. That pricing would lower the entry point (cheap enough that most people would not mind paying if they are in the mood to rush the game), while maximising revenues compared to the amount of content. But mostly, it would be a system that players would see as fair and balanced, and that fact alone would increase sales significantly.