For patent applicants in China, or inventors in China, the cost to apply for a patent of Invention and Patent of Utility Model is still a major determination factor. That is why you can see a lot of China originated patent applications are Patent of Utility Model.
This, as a matter of fact, created a large (relatively) number of patent specification that eventually did not go through any examination process. It is just too easy, in terms of cost and process, to get a Patent of Utility Model granted.
We have been approached to provide opinion for value of a granted Chinese patent, with a good story and a patent certificate. Quite often, we cannot put a value on it. This is a polite way of saying that it is worthless.