EOS is a long term ico, it has nearly a year to go, with 2,000,000 new tokens created every day. I'd be watching the ticker at the end of each cycle to see how many ETH are donated. From this you can work out how many tokens you are likely to receive. You'd also want to buy when ETH is not too high. Don't buy on HitBTC. I would think as time goes on you would probably pay less as it's not as fresh in peoples minds, but I could be wrong, it has happened!