[Nodachi]

I just don't understand why anyone would pay for a mod, regardless of how extensive it is.

What can you offer;

• New graphics - so what? If I were concerned about graphics there are plenty of other games out there. Besides, there's the Image Mod and all the different original shipsets out there. All for free.
  
• New components and facilities - again, so what? Anything you can come up with has to be workable with the existing game system. That means whatever you make can be done by someone else, for free.
  
• Background story (?) - We do that on PBW all the time, for free.
  
• Web support - How many other mods have web pages? Several that I can think of. Again, for free.

Look, I'm not trying to belittle your work, I'm sure you've worked hard on this. But so have many other modders on thier projects that they just give away for the enjoyment of the community. I thought that was what modding was all about, having fun and sharing ideas, not making money.
I think my biggest problem with a paid mod is this - Regardless of how much work you put into a mod it doesn't compare to the amount of work that went into developing and coding the game itself. To charge for a mod would be making money off of someone elses work, bottom line.