It's not worth $30.00 for the simple reason that it's commonly available for $19.99 or less. Buy it for that price.
With that in mind, it's a pretty good series for lasting less than a full season. There's a couple of relative duds--"Safe" and "Heart of Gold"--but that's par for the course for any television program and they are by no means unwatchable.
For a series that puts forward the idea that in the future the United States and China have merged into one power it's a little Amerocentric, but that's unsurprising for a series produced for American television.
The film "Serenity" is also worth seeing, though I'm of the opinion that it is nowhere near as good as the series, and it is by no means needed to properly enjoy the series.