Best software/service to batch manage & maintain Joomla! websites

I'm looking for the best solution to managing multiple Joomla! sites. There are lots of great solutions available for managing & maintaing multiple WordPress sites, but it's harder to find the perfect solution for Joomla!. What do I mean by best? In order of priority:

(1) Features. I would like the ability to batch install & configure extensions simultaneously for several sites, run batch updates, run batch backups, etc.

(2) Low cost. I would like a relatively cheap solution, preferably no more than $10 or $20 per month.

(3) Simplicity. Ease of use would be really nice, but I can deal with something that's somewhat complicated, as long as there's a good reason such as powerful, unique features.

Here's what I've looked at so far (none of which seem like the optimal solution, however it's possible I just didn't do enough research):

http://cmscommander.com
https://watchful.li
http://www.joomlalivechat.com/joomla-admin.html

Any ideas? I appreciate all feedback. Thank you for your help!