Many software shops have one person who is responsible for building an installer, while having one or more people who test new builds. It is a very common scenario. Often the developer is not the person who updates all the source code and builds the installer.
Request: A standalone command-line build-only no-GUI builder that can be used on a different computer than the developer's system. No editing or other functionality is needed other than build and rebuild. It would be a great addition to your product suite and could help sales if the builder was either included or licensed for less than the full product.
This is also true for shops that used continuous integration tools.