Is paid plugin but doesn't say so

You can install and configure the plugin, but to actually use it you have to pay.

I have no problem with people being paid for their work. However I think its against the rules of this website to advertise a paid product in a deceptive way. If it were said, somewhere, “You must buy this plugin at our website before you can actually use it,” I probably would have bought it. As things are, I feel deceived. Virtually all plugins here are free, and those that aren’t at least say so.