I have to agree with Dave on this but I do see all the concerns of others as potential issues.
But, in the PowerStore example, sometimes that is better for the client - but there is still money to be made. The client is not going to be able to reskin the solution to look appropriate and let's not forget the fact that there are some limitations with the solutions especially in the look and feel.
The reality with the a solution is that as a developer, we ONLY have to buy it once, and then we can deploy it as many times as we like... so think about the upside there - the developers can actually charge the client for a slightly modified version of PowerStore for, say $200 - the same price that the customer would get an unmodified version (and I'm only talking about making a few graphical enhancements... nothing major - if this was suitable for the project). But the developer could sell under that arrangement over and over again making the original one-time investment of $200 very profitable.
Of course, a pre-built solution is not always the best for every client and that's where the ability to sell comes in. Let's face, money is made based on our ability in sales. If we cannot communicate the differences effectively, we're probably not going to get the $2000 client anyway.