Visa costs to visit Beijing

My wife and son are going to be traveling from Hong Kong to Beijing to visit my oldest son who works for Beijing University. We shall be visiting for only 7 days in January and we are all UK Passport holders.

I was informed today that the cost would be £151 for the application per person, £453 for a 7x day visit!!

Is there not a short term visitor L type or any other cheaper way to visit?