Going from $10/mo to $77/mo for going from 10 to 11 users might be a big deal for a small company.
so you have 10 devs comp + benefits in 150-160K range(conservative estimate) and 670 a year will make much diff?
I think it's quite a nice introductory deal to get JIRA and Confluence for $10/month total for 10 users, since they let you keep that price regardless the time you've been using it.
I don't think making a comparison to the price for 11 users at $7/user is really fair.
It also looks weird when I see that the article lives on the vendor's own web site. There's no way Atlassian would title it like that.