Aeternity team have recently announced the launch of ERC-20 AE tokens on the Ethereum Network. It is expected to happen on September 2nd 2017.
During the second phase of ICO the minimum price of AE was about 0.00125 ETH (800 AE for 1 ETH), today it is about 0.48 $. However, the price of Bitcoin has doubled, but the price of ETH remained approximately the same in US dollars. It was possible to contribute both btc and eth during the ICO. Considering that a huge amount of ethereum was stolen during the security audit phase and the remaining part was in btc, it's likely that btc price will influence the price of AE more than ETH.
It's still unclear (at least I don't know anything about it) how "bonus" Bitcoin Cash will be used by the Aeternity team.
My forecast is that AE will cost at least 5$ at the beginning, and about 20$ close to Aeternity mainnet launch.