Recently we have completed 'Supply and Demand Tracker' for Star Trader 3000 game, that can be used in old Star Trader game as well. With it - price changes and trade calculations are much easier and are no longer based on 'maths' but rather on 'operations'. It will be included as part of Star Trader 3000, but - along with our policy - we've prepared set of files to help everyone out with our SD Tracker, including printable version of it.
To have it print this - PDF with SD Tracker parts
To use - read this - SD Usage Guide
Or watch walk-through - SD Assembly and usage