[Mr.Monkey]

How should we start ? I mean how we should choose a product for this ?  Is it better go for a high value product or go for a cheap ?

You'd usually want to choose a product on the basis of its purchase price AND its its demand. There is no point on choosing, for example, some expensive AKG or pro-headphones due to it being expensive and earning you more of a cut if there is no quite demand for it. Than to choose some generic or even Apple look-a-like headphones that will incite sales, and which in turn more sales from a lower cut that will superseed the few sales of a higher cut.

Choose and decide what will explode in popularity, usage, or praticallity, or steal from the current momentum of others and market a current existing product that is selling, depending on the price.