I wouldn't bother installing it even if Microsoft *paid* me to use it.
A turd isn't what I want on my plate even if it were cheap or if I was
paid to eat it. Maybe you're a fan of the Fear Factor television show
that tries to gross out its bribed contestants; for example:
Drinking donkey semen episode
Yep, that's to what I equate Windows 8. What you neglected to mention
is that to get the, ahem, "offer" means you have to BUY A NEW COMPUTER
during a fixed qualification period. Plus you have to buy that new
computer with Microsoft's Windows 7 operating system. Forget about
choosing a different OS (Vista or earlier or, god forbid, something not
Microsoft).
Eligibility Details
The offer is for customers (e.g. home users, students, and
enthusiasts) who purchase a qualifying PC. A qualified PC is a new PC
purchased during the promotional period with a valid Windows 7 OEM
Certificate of Authenticity and product key for, and preinstalled
with:
Windows 7 Home Basic;
Windows 7 Home Premium;
Windows 7 Professional; or
Windows 7 Ultimate.
You must purchase a qualifying Windows 7 PC between 2 June 2012 and 31
January 2013
So to get their offer means wasting money on a new PC that you don't
need to get an OS that you might not want to get an even more crappy OS.
Boy, are they desparate to up the sales count and market penetration of
Windows 8 that they know will do very poorly on its own for sales.
Where did you see the upgrade would cost £14.50 (which is about $22.42
USD - but that's at the interbank rate that YOU will never get)? The
site says the cost is $14.99 USD.