Well, I guess you`d better check for some reliable options rather than look for the cheapest one of smth for free. There is nothing like using some options that can satisfy your need on 100%! Still, it is up to you yo decide. I use this
vpn service for mac and should say it works pretty well for me and my family. It hides my IP address, surfs the web anonymously and I have unlimited traffic on servers with bandwidth up to 1 Gbps. So, I believe it is a good option for you. Simply give it a try.