From my recent experience with the official Toronto processing center (an efficient 15th floor operation which has been separated from the consulate for some time, thank goodness). There is basically one price, which varies only with processing time request and if it needs to be shipped back to you.
The 10 year business (M) visa requires an written invitation from an appropriate mainland company, preferably with ID from the Chinese side and they require some description of the business you intend to pursue. The cost is shown here- at the time of this writing it is $145.20 for Canadian citizens and $185.20 for U.S. citizens (CAD) for the cheapest (longest) processing time and self pickup/drop-off. As I said the price is the same regardless of the number of entries and duration of each entry. (there may be another price schedule for other than (L) and (M) types).
They generally have seemed cool in the past with traveling on a tourist (L) visa to trade shows and such like (buying, not selling or starting up a business), but that could change at any time, so the extra legwork for the (M) is worth it if you intend to pursue business.
The length of visa granted (if any) is said to be determined by the consulate. Having previous visas is apparently a positive indicator for getting more time, but the process appears to be a bit opaque. In my case I supplied color photocopies of a couple previous visas- which they included to the consulate so I know they were not superfluous- they gave me back another document they deemed not important- and was granted an (M) visa with 108 months validity, which they said was the maximum. Not sure why- but perhaps because I had an existing visa in an old passport still valid for a few months, and they probably require 6 months passport validity.
The visa form has not been revised yet to to include the 10 year option, so I wrote it in.