How are you going to keep the token price on the same level?
The token price will be held $0.1 till the ICO ends. After that it will be pretty hard to regulate it due economic laws. So we will not=)
As I understand unsold tokens will be destroyed. In that case the token price has to increase, right?
Correct. Lesser tokens > higher demand > higher price.
But the token price can be unstable. How to deal with the product's price setting in this case?
Merchant can set the price as in tokens, as in crypto/fiat.
We want to notice that GMC gives to customer more preferences and bonuses. So we suppose, as crypto/fiat, as tokens will be popular as payment unit.