Personaly I expect a certain "amount" of stuff from a expack, some are better than others but theres a "minimum level" and below that it feels like a ripoff. Thats generaly, in this specific situation I don't have enough information to decide but ill be buying it for sure. (Theres a sucker born every minuet and I'm right on time! heh).
Here is the cause of 'concern' for me: Most of the stuff in the first Mirpack is currently 'kind of' doable through modding. It requires some 'jury rigging' and the AI sucks with it ofcourse. What this means is what we are really paying for is the AI code to use the stuff (and its not like they particularly do well with turrets as it is), and possibly some special implemetations (buff types, module types and capabilites) depedning on how sophisticated they go with the design.
As I said I need more information, maybe thats not all they are doing (visable to the player at least, who would by an expack where nothing SEEMED to change but the devs assured us the back end is FAR better? lol).
TBH I would pay full price for an extended version of the engine with less limits and far more features to mod.
The people complnaing about the cost of the diplomacy mirpack (if its good anyway) are just whiners, don't listen to them.