My team and I are responsible for developing "one-offs", products that once finished are given to the client for upkeep or in some cases managed by us for a fee.
We still need to maintain a solid development pipeline to handle the constant feedback from our clients in order to ensure that we ship them something reliable and proven to run.
While the client doesn't care about DevOps (in most cases), it is still helpful for us. With DevOps, we can rapidly push new builds, so clients can see feedback in minutes not hours, and we are also able to catch any errors/bugs with our testing via Jenkins/Travis.
To ensure our deployment strategies are the same across projects, we focus on containerizing our applications. Using Docker, we are able to easily hand off the application to our clients.
The cost saved by DevOps is hard to determine. We do have extra costs in the form of software we choose to use for the pipeline (Travis, Jenkins, Puppet, what have you), but we also save time and money by fixing bugs/ giving the clients feedback quickly. Our quick response time keeps our customers happy, in turn, keeping our wallets happy.