Web Scape or manual look up of cities population

We have a file that has approximately 9,396 lines of cities that need to be looked up for population, many cities are duplicated and appear 5 -8 times, so even though there is 9,396 lines of cities its really about 4000 or so cities that need to be looked up and then that city population added for all the other lines that are the same city and state. The section you will work with is tab 2, column AB, every one of those rows of cities, the 9396 first rows, those cities all need a population added in column AB. The city and state appear in column AC and AD, It appears there would be a way to do a secondary sort after the AB column to stack the duplicate cities so when the population for each is added you then add to any of the same cities and state right below it. This can be looked up using google.com or wikipedia or any site that gives recent population for cities in the United states. This project will pay $150 dollars.