Our goal was to increase sales without margin decrease for some categories and to increase margin without sales decrease of specified products in other categories, according to Frisco’s strategy. We met this goal by adapting two concepts: price elasticity and market basket penetration. To investigate the relationship between the price change and market basket penetration for each product, we used a probabilistic approach. It allowed us to use different levels of price sensitivity, introduce expert knowledge into the equation, and gave the distribution of likely values. During the whole process, we gain a deeper understanding of the e-grocery industry, which we can transfer to other companies.