As for the treatment, as far as I know, it is the basic salary plus commission. There are workload requirements every month, and many cases have commissions. It may be a little less at first, and it should be more than 6 or 7 K when it is ripe. As for the upside, it is hard to say, it varies from person to person, but the leaders of the National Intelligence Agency, including the director, have been examiners.
As for the preparation, if there is a preparation now, I personally feel that the examiner in Beijing is unlikely to transfer to the enterprise.