The 'weakest link' line is a cliche that does not apply as a generalization for all categories of life.
Price does not equal increased performance.
Copper is copper. Period.
It conducts electrical signals the same way whether wrapped in expensive teflon or less expensive nylon. Its electron cloud does not change under such circumstances.
The "10% of cost theory" is old and based on someone's idea of what should be. It has no basis supporting any fact of performance increase beyond an individual perception of 'better'.
