Nowadays, software product line is an approach to reduce costs of software development, decrease time to market, and increase capabilities of reuse in designing and exploiting software development processes. Moreover, other quality attributes of the project domain should be considered to enhance quality of the product. Meanwhile, taking advantage of software product line makes developers capable of estimating development costs and time to market in a more realistic way. However, old approaches to estimate cost of development and foresee time to market are not suitable enough for software product line. In this paper, some important business parameters and a way to calculate cost and time to market in a product line are presented. Changing components among time, portion of the change in a specific product and organization issues are observed in the estimation function.