How do you unlock the cabal market normally please?
Cabal markets are established on "non-military" Tri-Tachyon controlled markets. This is in Corvus mode and Nexerelin's random mode too.
You can access the Cabal market by meeting these conditions:
1) Having good relations with the Cabal. To increase relations, make sure to 'donate' what they ask of you to them when asked.
2) Approach a market with a 'Cabal Exchange' with your transponder off.
3) Have enough credits to pay the 'entrance fee' (as well as buy their expensive hardware).