CP is not always cheaper. It greatly depends on the situation. Some people even with American born kids will have to buy tickets for the whole family. Furthermore, in certain countries you need to travel far away for your medical exam (e.g. Russian citizens have to go to Warsaw, Poland). Finally, a lot of people have no place to stay in their home country, so they need to rent an apartment or stay at the hotel. All this considered, CP may be way more expensive as compared to AOS.event though you have a low case number ,opt for CP.Its faster and cheaper(Even if you offset the flight ticket)