Extraordinarily Expensive. Not evidence based.
Total cost~ £200
This is a service for people with more money than sense, in which case, good luck.
For everyone else- I strongly suggest a discussion with your GP rather than getting these random tests.
Some examples:
PSA: a negative result can be somewhat reassuring in respect to a prostate cancer diagnosis, but only in the context of discussion with a GP. A positive result is non-specific (could be due to lots of things) but It creates a lot of worry, possibly a painful biopsy etc.
Thyroid function? If you are already treated for underactive thyroid then you should be having regular blood tests anyway. If you have symptoms of tiredness etc then you should speak to a doctor and not arrange this test. Tiredness could be an underactive thyroid, but also could be low b12, anaemia, stress, lung cancer, leukaemia, insomnia, Addisons disease, coeliac, obstructive sleep apnea, kidney or liver disease, low vitamin D or Folic acid, and many other things.
Bowel cancer? If you’re thinking along these routes then speak to a doctor and get a FIT test. It is far more accurate.
Random testing without the context provided by an experienced GP is at best of little use and at worst dangerous.