Pressero won't extrapolate between quantities automatically. Pressero calculates prices between defined quantities by calculating a per piece price and multiplying by the quantity the user has input. You would have to set up price breaks in your pricing engine. You would need to set a price for each extrapolated price change. For example, if the per piece price changes at 150, then you would need to set pricing for a quantity of 150 - in addition to a calculator parameter for 100 and another for 250.