Thanks for the replies guys!
are you saying that in the lite version you can't tag wikis?
Yeah that's right, there are a few things that are available in the pro version and not the lite version.
I also think it's important to factor in that plugins you pay for are more likely to be kept updated (essential at the very least to match WordPress updates) and if we rely on the goodwill of developers, we are playing a risky game, as they may just decide they haven't got time, or might fall under a bus and we lose a core feature.
Some people don't see it this way, so thanks :-) We have several full time developers keeping all the plugins up to date and adding new features.
I'm a firm believer in paying people for work, after all I expect people to pay me :)
As mentioned above you could sign up to get the pro version, then cancel, and just re-subscribe as and when you need updates :-)