Since we run two products (both Muck Rack and the Shorty Awards), we end up paying twice for some services like Github.
You can buy Atlassian Stash, once, for $1800/25 users, and use it forever: https://www.atlassian.com/software/stash/pricing
However for some, the task of self-hosting is daunting. I presume that is why some are willing to pay a lot for a hosted solution.
BTW -- It's worth noting -- BitBucket is run by Atlassian and allows unlimited free private repos. I think you must pay for teams (EDIT: Free up to 5 users, $10 per month for 10 users, etc, it's basically $1 per user per month over the initial 5 free), but just throwing that out there. It's basically their hosted Stash solution.
Not saying Stash is bad (the contrary), but when evaluating cost, evaluate all cost.
Local installations don't cost hours-a-month to run.