How can I move spaces between external monitors in Mavericks?
Solution 1:
You can only move spaces which are non-active.
For example, lets say you have spaces 1 and 2. If space 1 is active, you can not move it. You first have to select space 2 then you can move space 1 to a different monitor.
Solution 2:
TotalSpaces allows you to assign spaces and their contents to specific monitors.