Because OP doesn't come here I will help everyone asking about this. I still have a license to zennoposter 5 and ZP7.
This thread is for zennoposter 5. I do not think you can buy zennoposter 5 anymore for the 1 time fee + updates. You can contact zennolab on their website about it, since this thread is not maintainted.
Zennoposter 7, which is the current version offered on the zennolab website only has a monthly subscription now.