Nope, my bad, sorry - checked online and it is £3.74 for 0.25l (250ml), with white, dark grey and red also listed online. This states for garage floors: concrete, stone brickwork etc. Was this ever £14.99 for the smallest size, though? I wonder if they've confused themselves with their in store labels (surely an honest mistake and not trying to bend the rules!)? Green and white are £14.99 olive for 2.5l , whereas the others are £19.99, on their website.
Think you mean 2500ml / 2.5l, not smaller than a can of coke?!
Don't think it's store specific,probably best to phone your local store to check before you make a special journey ;)
Is it a store specific local deal?