You enter the level of ETH you want and it will calculate how much it would cost. Alternatively you'll be able to enter the level of fiat you wish to spend. The platform will compute how much ETH you will get. Learn extra about the denomination of Ethereum units. https://financefeeds.com/pi-network-price-prediction-is-pi-coin-a-buy-or-will-this-altcoin-pump-higher/