Saw this in Poundstretcher, Halifax (Crossley Retail Park, Pellon Lane) and was reduced from £19.99, to £14.99, now just £7.99.
They had loads in stock. They are right at the back of the store on the same side as the checkouts. I don't know if this is store-wide but worth a look.
I think next cheapest is the JML one on Amazon for £14.65
It's NOT the JML one but exactly the same! This is the one which hangs on the door frame, same as this http://www.hotukdeals.com/deals/jml-iron-gym-total-upper-body-worko/728309