Upon checking the Cherry Mobile SM North EDSA Facebook page earlier (March 1, 2015), they said that this device is still available on the said branch. In additiona, the device is on limited stocks on other Cherry Mobile stores in SM Malls in MOA, Manila, Cubao and Fairview and also at Ali Mall and Farmer's Plaza.
I wonder if the FS3 Octa will still be available in days, weeks or months to come as I saw this FB status post. We will find out thru the brand's social media pages soon.
Bonus: Thanks to this photo, we confirmed that this device has 1,800 mAh battery and it has 1 regular and 1 micro sim slot each.