As cdybeijing stated, Go books are very cheap over there. The rest depends on what do you want to do and where you are?
Generelly China is really cheap when it comes to local food (<2€ for lunch, less when you buy food on the streets [this depends where you are and you might need the right stomach for this, I ate "street food" and it did not effect me negatively most of the times]) and groceries (like Beer <50 cent ^^). Anything foreign will cost at least as much as in the west when not more - we bought a small bread and cheddar one time for >6€ in total.

Hotels are also cheap except for Shanghai, Beijing and of course Hongkong. Generally the less known the town, the less it will cost you (like everywhere). The biggest issue was always how clean the rooms (and the hotel in general) were or if the shower was working. If you are in a hotel, where no one speaks English, this might get tricky if you can't speak chinese. So better check beforehand, where to sleep.
This may sound off but hotels with something like a "Bath Recreational Center" are a lot cleaner. Just be sure, you - accidentely - don't drop off in the wrong floor then.

If you want to visit a lot of touristic places, this will definitely sum up. Prices are still kind of resonable compared to the west but compared to anything else in China, there are pretty high.

I spent ~1000€ excl. flight in one month while visiting Shanghai, Beijing, Hongkong and some not so well known places (+ the touristic stuff). I also had a suit tailored and bought a lot of Go books ^^ We went quite often to Starbucks since they had western food, coffee and free WLAN. So, you can spent a lot less depending on how good you can accomodate and how high you value cleanliness (some of us slept in the student dormitory and paid close to nothing).

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My "guide" to become stronger in Go

I would recommend you skip Shanghai and HK unless there is a specific reason
They are metopolitan cities just like any other and Beijing is enough
Try some of the other cities like Xian, Chongqing, Chengdu instead
Senseis wiki said Chengdu popular is for for go enthusiasts