Abstract CBSE (Component Based Software Engineering) is devoted to develop software projects in such a way that the final applications can be created by using plug and play generic components. It requires to properly choose the needed components from those available. However, that task is not simple at all. In this paper we present a way to automatically search, find and choose generic commercial components in a market of components. The method will be based on the specification of components in a standardized way, so that both customers and manufacturers can refer to them by using the same notation. Besides, both customers and manufacturers will give heuristics to estimate the costs of modifying the desired and sold components respectively. Then, the total cost needed to adapt a purchased component will be computed using both heuristics jointly, taking into account their confidence level. Hence, in order to choose the component that better fits his requirements, the customer will be able to take into account not only the sales price of the component, the confidence on the vendor, or the expectations of future versions to be developed, but also the adaptation costs.