Well, as I do agree to your statement the know how to handle money isnt the right way to put it.
Workers of the Colonial Benefiteds Countrys will try to justify their economical position, something near meritocracy. Besides that, felling like contributing to the theme!
Is not an option to expend money or dont, its a forced condition. There is no meaning in cash shops other than improve your experience and enjoyability of the game. So, as i do agree too to the reality of the F2P games you picture, in fact the business model (or the limits of our economical system regarding country boundaries and their economical exploits) tend to kill games, the MMO most, because why would you want to privilege some countries, or some pockets, if this all about more players better, in terms of needed design to match a higher population MMO (wich nowdays tend to be sandbox games, or games about everything).
Point League of Legends for example, the meta game and the design will be best each time the population grows, cause more people will be envolved in the game (wich is a colaborative thought process trought computers, wich is maths, wich is from the same tissue as poetry, right?).
So, other than vanity cash shops items in a MMO wich will have to get the LOL aspect to it, so the competition, if you put the money in it you sure had a less population in the rich countrys and proportional less on the other countrys, the 99% (LOL, jk).
And don´t forget that the avarege price of computers are and tend to fall, even something changes, the number of online people going up on poor countrys tend to be higher than the already heavy-internet ones. You have reach the limit population on games, so money could be extracted direct throught it, i guess that saturation isnt there even on those north countrys (the growing of esports for example).