The rate 1 ETH = 500 GNC means that GreenCoin Token is not cheap at its starting crowdsale price.
While ETH is still not very expensive, it turns out that you can buy 500 GNC-tokens for 1 air. It turns out that 1 GNC-token costs about 25 cents. It seems to me that it is inexpensive. Im probably investing a bit in this GreenCoin project.
You cannot discuss about price of a token without considering the total supply of that. For example A ripple costs only 30 cents. But it's not cheap when you consider the total supply and the total market cap.
total capitalization is the main factor affecting the price.
but there are other factors, such as the number of exchanges, the popularity of the platform, etc.