Will contracts between players be implemented in the next release in March?
Depends on what kind of contracts between players you have in mind. In the summary of our last stream Mjeno writes about the upcoming local market feature that will allow to create simple buy/sell contracts between players. That feature will be added during the next test.
Will those buy/sell contracts be available for use on planets where there is a Commodity Exchange?
Probably not. Right now we tend to only allow to build local markets on planets without a comex.
So the buy/sell contracts/bulletin system requires a planetary project to access? Is it expensive to build?
Yes and we want to make it quite cheap.