Please be aware that Beijing has multiple airports and that these results are only for Daxing International Airport.
The cheapest airline flying to Beijing is Capital Airlines. They are 61% cheaper than Hong Kong Airlines. (Average prices, based on 234 datapoints.)
At Beijing the most flights depart around 08:00. (Hourly flights, based on 382 datapoints.)
From Beijing it is on average the cheapest to fly to Guangzhou and to Xiamen. (Average prices, based on 134 datapoints.)
From Beijing most of the flights depart to Guangzhou, second best connected from Beijing is Chongqing. (Daily flights, based on 109 datapoints.)