SPAR Express

Saw a sign on the drink fridge near the front of the shop. It said " two 600ml coke for $5.99" got to the counter the staff said $8, I said the staff. The sign over there says two for $6 , that's an old sign staff says . I walk past the shop again a few minutes later the sign is still up. Is this just some way to suck people in to buy drinks only when paying for the items ??