If you are applying for a tourist visa, which is most often 30 days...
Must you booked more than a week of accommodation? Can you just book for 3 nights, since you are definitely not going to stay in one place.
I know someone people just get their visa through an agency or hostel, and they didn't have to book anything. But it is not easy to find agencies lately, who can get you the Visa. New policies require people to go directly to the embassy, which is also cheaper than the rate one hostel was charging in Vietnam.
When I've been to China in the past I got a visa at an embassy, listed places I wanted to visit and made up some dates and that was OK with them, though I did not stick to the schedule I gave them. No one checks.
If you book in advance you can book accommodation for your visa (if you think it is required) and use it if you want and cancel it if you don't want.
One agency in Laos, was charging 15 USD for hostle bookings, and it's just to produce a document that you have hotel bookings.
I've applied for visa's for China many times, but each time I went through a travel agent. They just just gave me a tourist guide to Beijing and said to pick a hotel at random. According to the Chinese government, I'm a regular at the Shangri-La.