Posted to an address ...

... in the UK
BUY NOW  1 pot - £12.99 (plus £3.85 p&p)
BUY NOW  2 pots - £25.98 (plus £3.85 p&p)
BUY NOW  3 pots - £38.97 (plus £3.85 p&p)
          - the recommended trial course
BUY NOW  6 pots - £77.94 (plus £4.95 p&p)
BUY NOW  12 pots - £143.88 (plus £9.90 p&p)

... on the European mainland
BUY NOW  1 pot - £12.99 (plus £13.20 p&p)
BUY NOW  2 pots - £25.98 (plus £13.20 p&p)
BUY NOW  3 pots - £38.97 (plus £13.20 p&p)
          - the recommended trial course
BUY NOW  6 pots - £77.94 (plus £15.30 p&p)
BUY NOW  12 pots - £143.88 (plus £18.50 p&p)

... in the United States
BUY NOW  1 pot - £12.99 (plus £22.35 p&p)
BUY NOW  2 pots - £25.98 (plus £22.35 p&p)
BUY NOW  3 pots - £38.97 (plus £22.35 p&p)
          - the recommended trial course
BUY NOW  6 pots - £77.94 (plus £28.00 p&p)
BUY NOW  12 pots - £143.88 (plus £36.70 p&p)

… elsewhere in the world
BUY NOW  1 pot - £12.99 (plus £20.30 p&p)
BUY NOW  2 pots - £25.98 (plus £20.30 p&p)
BUY NOW  3 pots - £38.97 (plus £20.30 p&p)
          - the recommended trial course
BUY NOW  6 pots - £77.94 (plus £26.25 p&p)
BUY NOW  12 pots - £143.88 (plus £31.15 p&p)