WTF do you mean "trial purchase"?

For those of you who have seen my youtube channel you may have noticed there was a brief period where i had a facecam and no watermark on my videos. Well, that was while I was using Camtasia Studio 8, or rather the free trial of it. Frankly, the program was fantastic and I've been saving up money so that I can buy it. When it finally comes to paying it, I see the print for what it says I'm purchasing "One software key emailed to unlock free trial for immediate use."

So my question is, What the hell does that mean? Am I paying for a free trial? That doesn't make any sense, why would I pay for a trial that is FREE? Do they even know what free means?

Most importantly, this thing cost's $300 US, If I'm having to pay $300 dollars just so I can use this program for a trial period they can forget it. I don't have that kind of money and there's no way I'll be able to earn enough from my youtube channel in that time to make it worth the trial.

For some reason, I haven't been able to find a single thing telling me whether this thing is a one-time purchase or if your have to pay to use it.

If anyone has any information on this, it would be much appreciated. Either way this whole situation has made me very aggrivated and it helped to get it off my chest, thanks for reading.