"Ending is better than mending" "the more stitches, the less riches." What do these mean and how do they support the motto of the World State?

In Brave New World, the World State
is devoted to consumerism.  The people of this society are conditioned to want to
consume goods and services.  There are at least two reasons for
this.

On the one hand, the consumerism is necessary for the
economy.  The economy of the World State is based on consumption.  If the people do not
buy a lot of goods and services, the economy will break down.  Huxley created this
fictional economy as a warning to contemporary society that it was excessively dependent
on consumption.

On the other hand, the consumerism is
necessary as a way to help keep the people from thinking.  Much of what happens in this
society (consumption, soma, sex, etc.) is meant to prevent people from thinking about
just how empty their lives are.  If they are buying and enjoying goods and services they
will not have time to contemplate their lives.

The quotes
that you give us reflect this focus on consumerism.  They encourage people not to save
old things.  People are encouraged to throw away old clothes rather than mending them.
 This is an example of how the World State pushes for more
consumerism.