They expect to launch each cube sat for a little less than 10 million each.

If Space can come up with a way to lift 20 or more at once then they can even take that launch service away from Virgin.
Considering they need to put 650 into orbit launching one at a time seems like a LOT of launches( and waste) considering the cube sats will be grouped into similar orbits to cover the same areas over the earth during a 24 hour period.

And couldn’t they have tried to use these liquid engines to launch their vomit ride into space instead of that hybrid pile they have been pushing?

And this tech was already proven possible 30 years ago.
http://en.wikipedia.org/wiki/Anti-satellite_weapon
They will be doing virtually the very same thing but using the White Knight instead of a smaller cheaper used fighter.