Lidl will have these suspernsion trainers instore from Thursday 13/02/14 for £14.99 which seems pretty good, it comes with a 3 year warranty too.
Product Information :-
Multifunctional sports equipment trains strength, coordination, balance and posture using one’s own body weight
With door anchor and straps for an extensive range of exercise and workout options
Includes exercise DVD with training instructions and storage bag
3 year manufactuer's warranty