Yes, I had this test many years ago when I was living in Britain. I recall that it is very expensive, perhaps prices have dropped now.
The results have been very useful for me as I've been battling migraine headaches for years (they're gone now) so I wanted to find out which foods were likely triggering them.
A few years later I read the book by Peter Adamo, "Eat right for your type" that suggests that we should eat according to our blood type. Surprisingly the recommendations were very similar, that is why I do not dismiss Dr. Adamo despite the heavy critisism of his diet.
I'm an O type, the oldest blood type on earth dating from the hunt gathering societies, so both approaches showed me that I do not do well with dairy and gluten-containing grains, I'm much better off with high-fat high-protein diets (I was a vegetarian back then with ill health; I did not turn to meat right away, but I have cut down a lot of carbs and dairy and focused on vegetarian protein sources and felt great!).
And a couple of years back I took Mercola's nutritional typing test that (surprise surprise!) said that I'm a protein type, so I should avoid grains and dairy. That is why I turned to TF, although I eat meat now I cannot eat too much and instead I focus on properly prepared legumes and gluten-free grains. No more migraines and my ongoing acne has cleared out for good
Bottom line: if you can afford it, then go ahead and have the blood test. If not, Dr. Adamo's blood-type diet is a good approximation and you can use his guidelines. This is what I did with my DS when I was introducing solids in the first year. And I noticed that whenever I tried to give him something not recommended for his blood type he rejected it (note: he was a very good eater, very chubby, great appetite)! My naturopath says that babies inherently know what is good for them and what is not, it is adults that they are no longer in touch with their bodies and feelings.