“Large increases in cost with questionable increases in performance can be tolerated only in race horses and women.”
Cost always matters!
Purchase price, more than the selling price, determines return on investment.
Be cautious about highfliers that may be closer to the end of their runs than the beginning.
That candy you can’t get enough of, for instance; the market probably knows it’s a top seller and has bid up the stock accordingly.
You could invest in the best company, but if you’re overpaying for it, you could end up losing money because the stock price already reflects the reason you’re buying the stock!