Domestic Algerian itineraries are incredibly cheap whether using black market or not. For example, ALG-CZL (a short flight) is US$31 one way in Y, $55 in C. We flew several times on Air Algerie and also on Tassili Airlines. Almost nobody in C, other than fast-asleep FAs on AH after the snack tray has been presented.
Another bonus for AH and SF C class pax is the tiny lounge with some juice and cookies, and your own personal bus transit on the tarmac to the plane, at least in ALG and I think in CZL too IIRC.