There was an EG article saying MT weren't in at launch but they were considering what to do in the long term. So AFAIK you can't buy upgrades yet. However, the game structure looks to me designed around the principle of MT, even if they aren't implemented yet. Hence my suspicion that maybe the economic model of the game changed during development. At first I'm thinking they were going for F2P with an MT driven economy, but finally settled on a significant flat-fee up front which works on these platforms and their users. They may roll out game on mobile with a different model, maybe, although I can't anything more than an old intention to port Frostbite to mobile.