Re: HND
In a word, no.
A professional photographer makes money by selling pictures, and working back from that, by taking pictures that sell. People look at the pictures before deciding whether to buy, not the qualifications.
Qualifications might help people to have confidence in your abiliities, but for my part I'd look at the "letters" offered by recognised organisations and trade bodies rather than educational establishments.
The positive value of gaining a qualification (I speak as one unqualified in photography or art) is that the course you follow will require you to study the parts that you find deadly boring, but whose content may well come in very useful later on.
From personal experience of taking a science degree (and I expect that this is true of whatever course you took) it is perfectly possible, provided you have the necessary motivation, to follow a course of personal study that will leave you just as well equipped. There are only a couple of exceptions to this:
1. Practicals. It would be quite impossible for anyone not incredibly wealthy to have access to the equipment I used as a chemistry undergraduate. NMR spectrometers and liquid nitrogen for example are not things you buy at your local DIY shop.
2. Examinations and essays. It's said that what you learn is what comes out of the end of your pencil rather than in through your eyes. It's easy to have a good understanding of a topic in theory, but it's only when you have a practical problem to apply the knowledge to that you see how well you've really understood it. This is partly a matter of self discipline too - you can buy exam questions, set yourself essays etc - or just try writing a book on the subject! You'll soon find out where you're lacking.
You can always try to find a group or web site where you will receive honest comment and critique on your photos. I'd recomments the Feedback Forum here - but I would, wouldn't I?
There are organisations you can join such as the SWPP who run a "Mentor Me" program.
£8,000 will buy a lot of private tuition, books, equipment (and even travel to places to try out the techniques).