Imitation is the sincerest form of flattery

It seems a new extension has been released on Magento Connect that provides integration with SecurePay's SecureXML payment gateway. I find this rather interesting as this extension is commercial, at a fairly substantial cost of $175, and provides the same integration as an extension I created back in September! Why would anyone create an extension that has already been released for free, then attempt to charge money for it?

I'd like to know if anyone actually forks out money for this.