I just picked up a planner to use for 2010. It was an 18 month planner, and even though it started back in July 2009, I didn't get 33% off the thing.
I also noticed that all the 18 month planners run from July to December of the following year. Are there a lot of planners that end in the month of June? Or do people who rely strictly on the 18 month planners just ignore Jan-June events every other year or are there 6 month planners that cover half the year?