Don't men buy the best tools they can afford for their hobbies? Don't all cooks look for the freshest produce and the best cut of meat that is affordable? Why would we as quilters not do the same?
We buy the best fabric we can afford (looking for the best price at the same time) because we believe that quality fabric looks better and holds up longer than cheaper fabrics. We want to make the best quilts we can, and that means using good ingredients, within the limits of our budget. We use the best tools we can find and afford, because they make it easier for us to produce a quality product. And good tools last longer and are often safer than tools of lesser quality.
Last but not least, we buy the best we can afford because --- WE'RE WORTH IT!