My example that I wish to use to disprove this claim is from inside a game.
A... friend - let's call them Postulatorian - has from time to time been known to play a game called Pokemon Go. Now while it is free to play, you can earn in-game coins and redeem them at the in-game store for items that will improve your game-play. You can also buy these coins from within the app, using (as I - I mean my friend is on Android) one's Play Store payment method. All very neat and convenient.
The picture below is of what the coins cost in Australia. I understand that this may not be the same in all markets, but the price difference makes me wonder why anyone would buy the bigger coin caches.
And so as a brief explanation, 100 coins costs $0.99. 550 coins should at that rate cost $5.445 - not $7.99! In fact, the prices for the large amounts should - if consistent - be (apologies for the formatting):
And so my friend has only ever bought 100 pokecoins at a time (using credits earned in-game or from the Google Rewards app).