[tialaramex]

Maybe you need to read more slowly, let's try just the essential two facts

"Alice has 40 oranges, and she's willing to part with them for 60p each"

See? Sixty pence.

"If we insist on having Alice's Oranges and Dave's Oranges but only paying 49p each for them"

We're only paying forty-nine pence for Alice's Oranges.

But Alice's price was eleven pence more - we are stealing from Alice

We're trying to determine a single clearing price, the oranges are just an analogy to make it easier to see why we can't choose the lowest price.

[happymellon]

What you did was take my original comment and try to make it more verbose.

Your "well actually" was argumentative and added nothing.

The solution is to either remove the expensive sources or change how we do the purchasing. Nothing you said changed that.

[tialaramex]

Your original post falsely claims it's the "most expensive rate". It's not, the most expensive rate is higher, often much higher.

What is paid is the clearing rate and I explained why. Fantasies about "changing how we do the purchasing" won't change the facts either.