Tianjin Airlines is offering flights to Tianjin, China for $490 return for flights in August and September. Flights include bags, meals and seats.
Skyscanner. These seem to be a couple of hundred dollars cheaper than other airlines. Seems to be a 4 star airline and is run by Hainan.
Tianjin. It's a cheap 30 minute high speed train ride to Beijing.
Tianjin is an interesting place and yes very easy high-speed train to Beijing. Once in Beijing the subway is convenient and easy to use for English speakers - a lot of work was put into it for olympics.