How much the cost bullettrain from Beijing to Shanghai

Well, the second-class seat costs CNY 410 and the first-class seat CNY 650. The ticket fare of the soft sleeper is about CNY 1175.
Actually, you can take the bullet train either at Beijing Railway Station and Beijing South Raiwlay Station, therefore, the price may has a little fluctuation.
By the way, if you wanna book a ticket in advance, the website may be helpful.
https://www.travelchinaguide.com/china-trains/