@theory -
According to the spreadsheet, 12 with base only, about 20 with Base + Pegasus and 1 with Base + Pegasus + Exodus.
Pegasus is really great and brings a lot of new stuff and fixes a few things, wouldn't play without it actually. New Caprica we only played once - and it wasn't all that fun. I'm not sold on Exodus, some great features (new 0/6 cards, loyalties, new attacking mechanism especially) but to me Lion's Head Nebula phase just seems too random - we lost 3 Morale (2 due to deaths) out of blue, at once, no way to prevent it, which really sucked.