Fitbit Flex Wristband in Black or Pink are price reduced to £53.32 at Sainsburys.co.uk. If you are a new customer, you can add a code and get a Fitbit Flex plus £7 of groceries and delivery for £46.00.
1) Go to Sainsburys.co.uk desktop site and search Fitbit
2) Add a Fitbit Flex (£53.32) to your basket
3) Add £7 worth of groceries/other items to your basket, so it totals to £60.00 (not including delivery charges.)
4) Choose a delivery slot for £1 or £2.
5) At the payment screen, enter coupon for £15 off:
RCNX-VDTC-7GM6 (first orders only, expires 08/02/2015)
My order came to £47.22, and I chose a £2 slot for tomorrow evening. If you choose a £1 slot you should be able to get everything for £46.
Edit: If you're ordering 2 in the same order, there's a code for £20 off orders over £100: NPVSFTF2D