A lot of people are speculating a price drop after mainnet but this may not happen at all or the drop might just be for a short period of time to shake out some hodlers (weak hands and probably people taking profit).

When Mainnet is live, people will start understanding the tech behind EOS, Developers will begin building DAPPs on it and If this DAPPs scales while Ethereum still battles with scaling, then expect a huge surge in price of EOS. Probably hitting $50 and above before year end.