If you just want to focus on trading, technically, any of the above could do if you dont progress along the storyline missions. It is probably the most 'stable' game and although there are main plotlines, it is not like the other two titles, so it probably more 'sandbox'.
X2 VS X3 REUNION REDDIT MOD
X3: Albion Prelude is essentially like a mod of Terran Conflict and takes place after the end of its plot. X4: Foundations is unique in its depth, simulating an entire universe of NPC ships and stations, forming a realistic economy. This will probably be very average, but my play. About This Game X4: Foundations is the latest title in the popular X series of space simulation / sandbox games, played as action games from a first-person perspective in a living breathing universe, with TRADE FIGHT BUILD THINK as the common tag-line.
From what Ive seen in the mods section of the egosoft forum, there are a lot of 'complete overhaul mods', the biggest 3 being XRM, LU and Mayhem (both v2 and v3 versions). The game was changed enough that the Reunion mods dont work on it Now Ive wanted to re-play X3:RE, but from the reviews I can see that X3:AP is a much more smooth and better overall game. Still has a main storyline and included new features. X3: Terran Conflict was the follow up game. There are two 'main' plotlines in Terran Conflict, one for the. Terran Conflict is set after the events of Reunion, and allows you to choose your player character from a selection of different starts. However the modding community was most active then and it has the most mods (Although its been years since Ive played so Im not sure which mods are still available) Basically, Reunion is a direct sequel to the plots of X and X2 (featuring the same player character as 2, and picking up right where 2 left off). Its the oldest game so there are features in the later games which arent in this one. X3: Reunion is the first game in the X3 series and has a strong main plot (Which continues from the end of X2: The Threat).