@Matthew2059 Its very simple once you know how! (and very difficult otherwise).
Just go to your calendar and highlight a months worth of dates. Then type in a new price. Then click a little cross (top right) and all the highlighted dates will unhighlight themselves. Go on to the next set of dates and repeat.
Similarly to block dates highlight them and then use the availability tab on the right to block them.
In said availability tab you can also choose to open X mths in advance or block all dates until you open them.