Simple the top ones are the hard copies and retail at 14.99pds the others are electronic kindle versions that retail at... £11.98
The original involved printing costs etc and you end up with an actual book, the kindle version only 3 quid less? Really? Isn't it about time that companies started taking the costs of online publishing seriously, stopped treating consumers as smucks and had prices that reflected the costs involved. Me I'm passing.
Or as they'd say it in the classic Outlaw Josey Wales: