I agree with Doug for this case.

On top of that, I like to add my view that although MoS, by language, sounds like a quantitative measure, but in real life it isn't one. To me, it is more like a qualitative judgement of feeling safe.

For example, we don't calculate how much impact a door can sustain in order to feel safe (though very few still do, I think), but we observe the quality of materials, the producer's reputation/branding, the technology of the door-lock and whatnot.

Same goes to investment. We don't know EXACTLY how much the discount-to-intrinsic-value we need for EVERY investment in order to feel safe. We may feel safe to buy Apple Inc at merely 5% discount to intrinsic value but we would insist for 50% discount to buy Blackberry Inc. That's more about art than science.

And that's how Mr. Buffett evolved into buying great companies at not-so-cheap price, because he felt safe with those prices and the moats of the companies.