If you want to just drink tea, and not having dim sum, there are now some tea places for that. I know there's one in the basement of the Seibu department store in Pacific Place. And I've drank tea at the tea house at the Heritage Musuem in Shatin. There must be other places to do so too.

Cheapest seem to be around HK$20. There are some leaves that go over HK$100. They give you plenty of tea leaves in a can so you can change out the leaves 2-3 times.