Will there be any mechanism with which user can convert his/her boosts into FIAT or GZR?
Probably they would put a mechanism in the system to just buy gzr with fiat for this kind of things.
You can't expect a player abandon his game buy some gzr from exchange and send it to hiss gzr account

I am talking about an option like there's paypal to buy the boost tokens.
What if I want to sell my boost tokens ?
It is important to understand the difference between Boost and GZR. Boost is the in app currency of Gizer. Boost can be used to facilitate different transacitons on the Gizer network and is tied to fiat currency. It is currently used to facilitate tournament prizes, pay entry fees and redeem cash rewards. GZR tokens represent an unlockable profile item tied to a users Global Gaming Identity. You won't able to buy and sell GZR on the app from day 1, but we have many plans to greatly increase the utility of the token. We'll talk about a bunch of these options, as well as the legal issues involved in one of our
upcoming Medium posts, make sure to keep an eye out. Our team is committed to keeping everyone updated on exactly what our plans our regarding all aspect of GZR and the token sale! Since a lot of people are interested in this its a great thing for us to write a blog post on!
Intriguing, an in-app currency pegged to fiat. Boost is only mentioned once in the whitepaper. Where can I find more details about the implementation of Boost?