I'm going to consider this as a genuine question rather than an excuse to say something inflammatory. The implied volatility of an underlying is the market's forecast of the standard deviation of the returns of the decreasing maturity forward of the underlying to the expiration date as measured by any fixed or variable time interval, assuming lognormality of the asset. If you for whatever reason disagree with the market's assessment of the value of this measure of asset volatility as implied through inverting options prices using the B-S formula, then deal an option and trade its gamma how you think is most profitable. If the actual realized volatility ends up being different from what the market had implied when you dealt, then you should have either made or lost money. There's no reason why you should need a measure of volatility to price the linear underlying itself. Local volatility takes a volatility smile as an input to price european style products. That includes vanillas. To mark a vanilla smile yourself to begin with, get the prices of at the money options and two or four other points on the smile and then either just use a spline (or another numerical interpolation-extrapolation method) or sabr (or another model based smile).