If you want a cheap flight from Dundee to Beijing, you've got zero airlines to choose from.
Beijing Capital Int. Airport is just one of the airports in Beijing. If you're not set on a specific airport, try changing your search from Beijing Capital Int. Airport to Beijing to see a broader range of flights – they might be cheaper. Airport.
You can expect accommodation prices to be higher at this time of year too. Last-minute deals do crop up, but it's best to book everything in advance to avoid disappointment.