For the most part the tours are free, and often include some kind of sample cup of tea at the end. The samples are often made by a tea expert, and can turn you into a tea snob instantly. Their expectation is that you'll buy a bag or two at the gift shop on your way out and in many cases this isn't a bad idea. You will find that locals also offer tea for sale at local stands and in some stores, this tea isn't as high quality as the stuff at the factories, it's cheap, but for a reason.
The tours themselves are often short, and there isn't too much in the way of explanation of the tea making process. They also don't often, or ever, offer tours of the actual tea fields. If you want to see a tea field it's fairly simple as they're all around the plantations. Roads will cut right through them, and there are pathways that crisscross around them. Walking on these pathways is generally not a problem, although you don't want to venture too far, and damaging the tea plants is frowned upon.
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