What you're missing is that there is a difference between information that comes from Searchtempest and information that comes from Craigslist. Telling you that there are 82 cities within your search radius does not require access to craigslist, because that information doesn't change. The craigslist cities are always in the same locations.
Each 'Show more' click is not equal to a request. Regardless of how your search is performed, it requires 82 requests to craigslist's servers - one for each city. By breaking it up, I ensure that these do not all occur at the same time. I also guard against people setting their search radius to thousands of miles then only looking at the first few cities.
