This is the real way to hurt a company. Once an open source version exists, even if it is not as good as the commercial offering, they will have trouble convincing people to pay for what they are selling.
Of course, they should be compensated for their work, but if you can build it yourself then the cost to a company does not need to be much higher than the costs of parts and labor for someone else to do it for you.
One of the things I want to do is build decent applications and release them for free so people can get the same functionality of their paid apps but not need to pay anything.
Main thing stopping me is time.
