Can tintable primers be used alone?

pieroabcd

Hi,
At b&q  I've seen a Valspar water based tintable primer.
So far I've never used primers, only matt based coloured paints, two or three coats.

If I used a tintable primer could I get a good result with a single coat only?

The tint that I'm using is a light gray with a slight tone of light blue ("morning song"). So far it's looking well, except that it reflects too much the light (I can see on the wall a reflex of a sticker on an appliance).

If I could get the same result with one coat only it would be cheaper. These paints are really expensive.

Thanks