Was I ripped off in China?

Last year I went to Shanghai with my dad. We ran into these three Chinese tourists (two girls and one guy) who were about my age, who wanted to have their picture taken with me (I have blonde hair). We practiced our Chinese with them and after talking for a while we were invited to go have tea. The tea costed a lot of money and didn't really taste like anything to westerners who never drink tea. After that we spent a the rest of the day and the whole next day with them. Everywhere we went after the tea shop wasn't expensive at all, in fact I'm pretty sure all the meals we had cost less than the tea did. They were very nice people and I still keep in touch with them but I've heard this tea thing is a common scam. Later we I was in Beijing and we were approached but two college students who wanted to have tea with us, that also happened to be very expensive. At that point we were sure that we had been ripped off twice, but it still torments me that the first people we met spent the entire day with us. And we had a good time to, I pretty sure that wether they scammed us or not the genuinely liked us it didn't feel like they were pretending. Does tea just cost a lot of fucking money in China? Or were we cheated twice by the same scam? Probably the most convincing evidence that supports this all being coincidence is in both cases we took pictures with them and they gave us their phone numbers (which worked) which we could give to the police. I have a feeling that I'm jumping to conclusions due to my ignorance of eastern culture, tea is a big deal there maybe its just expensive. However a few weeks ago a friend of mine told me about a friendly couple she met in China who invited her to a tea shop...