Here's a good, proven reason why the New Extra Boff and Ship Slots cost too much.
Cryptic Charges 500 CP for 2 Extra Characters. That's 10 officers, 8 Ships, A crap load of recorded Accolades, A Crap load of recorded missions, etc. Then they decide to charge 400 for 2 extra Boffs/Ships... The extra boffs/ships take up nowhere near as much space as 2 extra characters.
Even if the Extra Boffs/Ships were account wide, it still probably would not take up as much space as 2 extra characters (well, if you bought a LOT of chars, then bought an extra per account pack, the pack might take up more space, but that's a rare case, at best).
So, Cryptic, How about this? 100-200 CP for 2 Extra Boffs or Ships, account wide.
Database impact should not have an influence at all with C-Store prices, and here's why. We all pay a monthly subscription-- this should at least be enough to cover server maintenance if it's not covering development time. I don't disagree with you that these things should be vastly cheaper as a per-character service...