Investments:
£7.48 on the site - see
here
Not actually true. The deal is for a Stealth Power razor together with the big gel and a couple of blades. The link you've given is for a standard fusion manual razor with no extras.
I went into my local store this morning and they had several sets comprising a fusion power handle, 2 x blades and a big Hydra Gel. They were £4.99 each, I'm assuming its the same set the OP was referring too. My store obviously not as generous with the markdowns as his, however even at £4.99 a good price.