Now I see a tendency towards asking unjustified amounts of money for plugins not offering all that much to begin with or offering features which should be standard issue in a professional forum software anyway, like f.e. changing usernames ... omg, yes?
I see f.e. SMF which is a great forum software; I use it myself (also in combination with Subdreamer CMS) ... wonderful. And there are tons of good plugins, of course 90+% of them free or mostly for very fair prices.
xenForo itself is very expensive to begin with and this tendency for high priced plugins, I see that xenForo will not incorporate those functions or evolve, thus not disgruntling the 'developers' here. I say 'developers' with hyphens, cause what I see in the resource manager, I can do almost all of it myself, no big deal and/or mostly ports from open-source PHP projects anyway.
I am very concerned about where this going and I also see the cost of ownership of a decent xenForo rising to > 500$ ... sorry but no-go. Just my 2 cents.