As writen in the white paper on page 10 the costs of the ico are:

presale 1ETH = 2677,50 tokens
Day1 1ETH = 2231,25 tokens
Day 2 - 7 1ETH = 2052,75 tokens
Week 2 1ETH = 1963,5 tokens
Week 3 1ETH = 1874,25 tokens
Week 4 1ETH = 1785 tokens

at the current price on hitbtc you get 2677,5 SISA for only 0,898 ETH.