I remember when this all came about.
It is free, unless you want those additional services. I never ran into the issue myself, but my understanding is that there was a lot of confusion around the licensing which was simplified. Soon after that situation, another blog post, which I can't seem to find, where they changed the licensing and made it simpler.
This was the response to your forum reference: http://www.appcelerator.com/blog/2012/10/please-review-proposed-license-agreement-changes/
http://www.appcelerator.com/legal/appexplore-agreement/
Titanium Studio at the App Explore level is a free closed-‐source commercial product subject to the terms herein. Use of Studio under App Explore is provided absolutely free of charge. Use of the Appcelerator Analytics and/or Appcelerator Cloud Services is free up to a certain tier found at http://www.appcelerator.com/plans-pricing. You may incur fees or have certain usage disabled or reduced for usage beyond the free App Explore tier as set forth on the Appcelerator website. No support or other services will be available from Appcelerator under the terms of this Agreement at the App Explore level.
You can use it for free.