Will you buy some dog food before buying a dog just because the dog food is cheap?
Logically, you won’t.
However, we always do this in our daily life.
We buy a pair of earrings we like
never sense that its colour doesn’t match any of our clothes
we end up buying another set of clothes just to match the earrings
We wake up a friend who is sleeping soundly at night by a phone call
just because the night call is cheap.
We end up annoying the friend in bed
Food that is unhealthy
Things that we never use or need
Buy only those which suit you.