A readout scheme for achieving quantum limited displacement sensing of high frequency mechanical oscillator is presented, whose frequency greatly exceeds the cavity decay rate used for parametric motion transduction. The coupling of a mechanical degree of freedom to several optical modes spaced by the mechanical oscillator frequency allows substantial reduction of the power required to reach the standard quantum limit, compared to the case of coupling to a single cavity resonance. Moreover, quantum back-action is enhanced in this scheme, relevant across a wide range of quantum-optomechanical experiments. Straightforward implementation of the scheme in both microwave and optical domain is discussed.