It’s a risky purchase because you can’t see it directly. Buying software that was written specifically for you only adds to your risk:
These risks create a disconnect between your investment in the project and a visible, tangible return.
One extreme of this disconnect is when you don't see anything from the developer until the project is completed. It's a black box. You provide inputs like funding and feature requirements and out the other end comes a completed project. This approach is the highest risk because Investment and Visible Return are completely disconnected until the end.

A less extreme disconnect between Investment and Visible Return is when you have periodic opportunities to revise your requirements and to evaluate the progress of the project. The more frequent these opportunities, the lower the risk.

Until finally, in a perfect world, you could revise your requirements at any time and you would always have complete visibility into the status of the project.

Of course, the perfect world of zero project risk doesn't exist. But can you get close? What are risk-reducing characteristics in a software developer that you should look for?
You can expect that this is the approach Waverley uses. In fact, we've organized the company around reducing your risk. Our intention is to constantly find new ways to approach that perfect world of zero project risk.