Using itertools permutations and combinations to find an optimal route through hotels and cities

I have gotten barely anything done, as I am not sure how to approach the problem. I am having trouble because I need to find a way to find permutations of hotel costs with a maximum of $850, and a route through cities with the highest average temperature. The cities are a fixed dictionary with the city name being the key, with a list of the temperatures as their value. I am a student, and working for my Bachelors in Cyber Security at Embry Riddle.