It will start at 64GB. This is not the starting peg 100%. We are starting it here to analyze the network.. Then a peg will be deicded, and it will begin scaling from there.
I still can't imagine how market will react to this UNIQUE feature. It's like the coin will go form 1$ to 5$ from a day to another?
The whole crypto space will try to buy it, then??
Once it is pegged, nobody will want to buy it anymore because it will stay pegged?
Could someone enlighten me?

At first there would be some time for the market to adjust to the peg, after that you'll have a stable coin... until the smart contract rises the peg to the next step. If you think nobody will buy a stable coin you should have a look again at USDT volume graphs.
We still don't know the final values that the smart contract will use so the peg may increase to maintain price or to make it grow, or even not make it grow enough to maintain price.