Beijing is become expensive.
Beijing is more expensive than ever these days. Still value for money, but you really notice the difference when traveling elsewhere in China. Subway fares are now distance based, but still cheaper than taxis. Some shops are just overpriced, and for convenience items it pays to look at prices in a few not just buy from the first one you get to. For cheap food eat where the Chinese do, the small, places are usually the cheapest and tastiest.
Insider Tip:Walk up the Hutongs for cheaper food, but beware some vendors selling items for more to foreigners. Be prepared to walk somewhere else if you think this is the case.