In reply to christicehurst.

Well, it is open source, so I highly doubt they're doing anything "by purpose" to "force" you into buying anything. Anyone is welcome to fork it themselves and try to make a version that's lighter on requirements. You could even contribute the same back to the project: http://github.com/discourse/discourse

Anyway, I'm not sure why the requirements are so high myself, maybe it's all the stuff under the hood, but you can certainly ask them about it: https://meta.discourse.org