Marks states nothing is a good idea in the absence of price, lesson from Nifty Fifty experience.
“But the lesson I learned from my experience with the nifty 50 in '69 was that it's not what you buy, it's what you pay that matters.”
Marks states good investing is not buying good things but buying things well; price determines risk.
“it's not what you buy, it's what you pay that determines whether your investment is risky or not. B, that good investing is not a matter of buying good things, but buying things well.”