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.
Does it mean that the product price will be automatically changed in case of token price fluctuations?
The price will be decided by the merchant, if it is represented (NOT FIXED IN) in GMC tokens (e.g. product price is originally fixed in USD, but is displayed in GMC), in this case, yes, it will be recalculated automatically every time GMC token rate changes.