I noticed the falling price of Promotion! Bug ship packs, and took it upon myself to do some testing.
I opened 17 stacks of the promo packs on tribble, and received 17 bug ships.
This tends to indicate something approximately 1/100 for the chance of gettine one.
Now, if a lobi ship costs 95m, then 1 lobi is worth 118,000 ec.
And a Romulan Survivor Doff Pack is 1.9m.
So, for each Promo! pack you open, your expected value is (450m / 100) + 1.18m + 1.9m.
Or, Almost 7.6m ec!
These are strong positive odds! Promo! packs are priced far below their value!
(note, I accidentally opened one of the bug ships during this test, so there are only 16 visible)