Colgate Advanced Whitening 100ml Pump and Sensation Whitening 100ml Pump are both currently better than Buy One Get One Free at Tesco. They are £2.99 and £2.62 each respectively, but 2 for £2.50.
Asda has some 100ml pumps of Colgate toothpaste at 2 for £2.50, but these are the cheaper varieties. In there, the Colgate Advanced Whitening 100ml Pump is £2.99 with no multibuy. In Sainsbury's it is £3.00 with no multibuy.