Add on the mandatory meals cost plus the service charge and a single person on a one bed will be looking at just short of £500 a week.
But it is for people judged able to live independently with some support.
It cannot be compared to Nursing facilities where 24hr professional nurses are on site. The average cost of nursing facilities is circa £1500 a week.
It is as you say a private initiative and the investors expect, not unreasonably to make a profit.
For those who can afford it but need limited support it seems a worthwhile initiative.