[JohannesH]

Short answer it depends on your needs and you comfort level with server management. But generally I would say a server running something like Jenkins or similar is not that taxing on the maintenance budget. It does have some up-front cost in getting everything configured and running as you like but after that it is fairly easy to maintain. I usually automate the provisioning as much as possible both for the self-documenting aspect but also to make it easier to repave the system or spin up additional nodes as needed.