Sins of a Solar Empire - Trinity
This new bundle pack includes the original Sins of a Solar Empire, plus the
Entrenchment and Diplomacy expansions.
Link: http://www.impulsedriven.com/sinstrinity
This is the cheapest they've sold all three combined. The last Sins of a
Solar Empire sale was $4 for the original game and the last time they had
the expansions for sale they were $15 for both.
Another game of note, is Sword of the Stars Complete: http://www.impulsedriven.com/sotscomcol
for $5.99 ($2.00 cheaper than on GamersGate)