These elite stocks are perennially expensive. Consider jumping on them if marketwide turbulence drags down their prices.Bull markets are fun because stock prices go up rather than down. The downside is that top-notch stocks often rise to excessive valuations, which can diminish their long-term return potential. Recently, volatility has begun creeping into the broader market after mostly good times these past few years.If these expensive but otherwise exceptional stocks begin falling to more attractive price ...