been to beijing about 8 times now. and i am a drinker. all the comments above seem ok. however when you go to the bar areas you can expect to see a lot of guys outside trying to get your business. ie. come to this bar and offering a little promotion. you have to HAVE TO AND MUST haggle or bargain with these guys. the beer comes in mostly long neck bottles and you will pay around 3 euro per bottle or more. but you must haggle and you will half this.
if you sit and eat in the basic (local people) restaurants you can get your beer for very cheap about 20 cent euro. but be CERTAIN there is no miscommunication on the price. be very clear first. for example the tsintao beer has different variations. and if you dont agree the price you can be guaranteed the girl will serve the expensive tsintao (wrong spelling i think). in the little shops the beer is really cheap. and if yhou want to be very clever just bring back the empty bottles and get discount on your next beer purchase. brilliant. and as an aside if your buying american cigarettes dont get them in the ciggy shops they will con you. they are all fake. and will charge around 16 euro per 200 pack. so be very careful there. prob better to smoke the local brand cheapy ones.