You're not going to get that long. The difficulty takes a bit of time to adjust to sudden increases and decreases in hashrates. It'll likely settle to around $6-8 unless the coin value jumps, and then lower when the next batch ships.
Right, or when You notice big network hashing power increase. You will know that Bitmain and Innosilicon start mining in silence with new 2 Mh/s beasts....