there is no way to know the "exact" price of any coin because the developer of coins does not control the price but the trader/holder/buyer/seller itself, its not centralize so no one control the price. Price will always vary from different different exchange.
I agree with you because the facts are like that.
The development team cannot manipulate market prices, because the market is owned by traders and buyers.
If there is manipulation, then it can be said that the name is monopoly and the nature is centralized