If you are seeking to build a focused platform with custom, proprietary software the decision will be guided by a time / functionality trade-off. There should be no doubt that building custom software will take more time than using readily available, off the shelf solutions. This may result in a custom platform specific to your needs, but it also means that most of the componentry must be built from scratch. In terms of functionality, the custom aspect can also have its disadvantages. Most importantly, will customers be willing to learn how to use your software platform? The more unique the look and feel of a platform, the more it may turn off potential users.
Try This: If choosing a custom software choice, ask the programmer for as detailed a work scope as possible. Get a full understanding of the time it will take to build your project and where potential delays might occur.