Boots have these special Gilette value packs in store and online for £20, the ones I've seen are:
Gilette Fusion Power Razor + 9 spare blades
Gilette Fusion Razor + 11 blades
Gilette moisturiser + 11 Gilette Fusion Blades
Gilette Mach 3 Razor + 14 blades
Moistureriser + 14 Mach 3 Blades
The second one was in low quantities, but I managed to pick one up from Lewisham.
The RRP of the blades and razor in my deal was £31.71, a saving of £11.71, which is alot really.