org-priority-start-cycle-with-default

org-priority-start-cycle-with-default is a variable defined in `org.el'.
Its value is

t

Documentation:
Non-nil means start with default priority when starting to cycle.
When this is nil, the first step in the cycle will be (depending on the
command used) one higher or lower than the default priority.
See also `org-default-priority'.

You can customize this variable.