I have virtually everything available for GC3. At least for now. 
I just purchased & d/l'd:
- "Builder's Kit DLC"
- "Rise of the Terrans DLC"
I also have:
- "Mega Events DLC"
- "Mercenaries Expansion Pack"
- "Precursor Worlds DLC"
- "Revenge of the Snalthi DLC"
- and the soundtrack
When the game loads up from STEAM, the main menu has MERCENARIES as the background (so I guess I'm in the MERCENARIES expansion pack game) & I'm on v1.8.
How do I get access to everything else??
Thanks for the help!!