Actually that's one point where you are not correct. For a good email campaign, it's imperative that you manage your list. You need to be looking at stats from the previous campaigns and making changes for future campaigns. If you have a lot of low-engaged/no-engaged emails, you need to try to re-engage them and/or drop them from your list. If you send 1 email a week to an address for 5 years that never opens, you are literally throwing money away. MailChimp (which we use too) has a lot of very good tools to help prune your list and glean a lot of insights into your engagement rates.
> Paying someone to micromanage the services to get cost savings would cost at least $60,000
Not necessarily. Download a copy of Openfire XMPP server, stick it on one of your spare windows/*nix boxes in the corner, and it will run un-maintained for years. Just cron/schedule the OS updates automatically and it takes no more effort/skill than logging into a website to manage user accounts.
And nobody says they need an expensive seasoned SysAdmin to manage these services. Hire a college student for $15-$18 per hour part time to come in and tidy things up.
There are other opportunities to be had with their list of services, such as taking advantage of the drastically lower cost BitBucket (if they must have their source code repo's external).
There's certainly a lot of waste listed here.