In 2012, Mindjet announced a new pricing methodology, changing their sales model to a subscription-based one; it was clear to everyone that Mindjet was not looking anymore to their large customer base made of individuals, small businesses, entrepreneurs, students, non-profits, loyal users of Mindmanager.
The complains raised immediatelly as we can read in Mindjet's own discussion boards and in Chuck Frey's blog post (links at right); users were then looking for cheaper alternatives to Mindjet Mindmanager; luck of us that there are many good offerings in the marketing, all of them easy and free to try.
Hearing and acknowledging all these complaining loud voices, Mindjet then announced (May, 4th 2013) "The Next Generation of Mindmanager" with the motto "Now Get Mindjet MindManager for Both Windows + Mac at One Low Price". A clear shift on their strategy, realizing that Mindmanager is a more powerful brand than Mindjet and that they do depend on their loyal customer base.
This list of Mindjet Mindmanager alternatives is the result of my own quest for a substitute. It does not intend to be the most complete list on the internet, but I hope it will be a good starting point for you.