Three perspectives
Cost approaches consider the resources required to recreate or replace an asset. Market approaches examine relevant transactions. Income approaches consider future economic benefits and risk. These are perspectives to assess, not three prices that should automatically be averaged.
Evidence determines what is useful
Comparable deals may be scarce or have materially different terms. Development spending may not reflect commercial potential. Forecasts depend on assumptions. The UK Intellectual Property Office explains these limitations in its guidance, linked below.
Start with a defined brief
Before choosing a technique, explain the asset and the decision. Agree the valuation date, basis, information available and intended users. A scoped engagement should document its assumptions, limitations and permitted use. Tax, litigation and financial-reporting purposes require specific consideration before work is accepted.