I am wondering if there's a website that provides the price of the standard gas limit (21000 Gas, transaction cost for sending ETH) in ETH unit.
I checked Ether.Fund site, but it provides the gas price in BTC and is based on ether pre-sale rate.
There is no fixed gas price that transactions must have.
You can specify the gas price, and if you set a gas price within certain bounds, the transaction will be accepted by miners using their default values and oracle.
The default gas price is now 0.02 microether which is equivalent to:
When you send ETH, your client (Geth or Parity) will use the default gas price of 0.02 microether.
If 1 ETH is $10, 1 gas will cost
0.00000002 * 10 dollars.
If ETH is $10, 21000 gas will cost
0.00000002 * 10 * 21000 = 0.0042 dollars, which is 0.42 cents.
If ETH is $1000, 21000 gas will cost
0.00000002 * 1000 * 21000 = 0.42 dollars, which is 42 cents.