Continuous commodity market

I've been making design changes to the NPC commodity market such that supply and demand is continuous, instead of being reseeded during downtime. This should level the field for all players (especially Australians), as well as making price dynamic more rich. At the same time it will probably be a good idea to revisit some of the parameters there, such as distribution, price margins and volumes. To summarize the change, you can basically think that the same amount of supply (and demand) as before will now be trickled in continuously instead of once a day. This means that no player can get a chance to buy up the whole supply of some commodity. Furthermore, prices will be dependent on over- and undersupply at the given station. The impact of these changes should not be so great on existing code, but some internal changes to the market logic needs to be done, along with some minor DB changes. No client patch should be necessary. If you have some brilliant (simple) ideas about this subject, now is the time to let them resound, in case some of them would fit nicely with the planned changes.