Assuming that hotdogs are substitutes for hamburgers, if the price of hamburgers increases, what happens to the market of hotdogs? If hotdogs are a substitute for hamburgers and the price of hamburgers increase, then the market for hotdogs will increase. Due to the hotdogs being a substitute for the hamburgers, if their prices do not rise but hamburgers do, people are more likely to purchase the hotdogs over the hamburgers to save money. Assuming that the hotdogs price do not rise in relation to the hamburgers rising, then there will be an increase in hotdog sales.