Clearly not Cyphotilapia frontosa "Burundi", or any other C. frontosa collection point.
They are Cyphotilapia gibberosa.
Of which type, most likely a Tanzanian type. Though i have seen plenty of Blue Zaire's that had faded coloration, they in general are not dark or blue enough.
also, the mask is more indicative of a Zambian or Tanzanian type than a Blue Zaire type.
The one juvie in the lower right corner looks like he is a Zaire hybrid.
so perhaps they are a collection of mutts, but IMO as a group i would not class them as BLue Zaire.
There is also some mooning in the group, so avoid those.
If you don't mind buying fish of unknown history, the price is fine.
give them a call, maybe they can tell you more history of the fish.
If Zaire they should tell you if they come from Moba, Kitumba, or Kapampa etc stock.
If they say, "i don't know, a customer brought them in." then chances are they could be mixed or just about anything.
when breeding Zaire, they are very hard to breed compared with other frontosa.
some people will cross them with other frontosa types because its easier to breed that way, then sell the fry based on what they look like.
crossing 2 types will get you a range of looks.
If the fry come out looking like zaire, they sell them as zaire.
if they come out looking like mpimbwe, they try to sell them as mpimbwe or just dump them at the LFS.