So I left a bar at the same time as my friend in Microcentro and both of us went to Palermo. My plan was to take the collectivo home and pay 2 pesos. He doesnt take the bus. I felt wierd saying so long, I'm going the less expensive way home and we got in the same cab. The price to my home was 35 pesos and I gave him a 20. It would have been almost the same time on the bus and certainly a better value, but I felt awkward saying, "Chau! I'm taking the bus to the same neighborhood even though you don't want to". What is the normal behavior in this situation?