From your other posts you are on a PPPoE (presumably xDSL) connection. I wonder if the actaul connection is limited in terms of a monthly traffic amount if it's worth to put some kind of traffic limiter on the VPS's connection.
Do you want to provide VPSs/services to other people or is it just for personal use? If you provide services to other people I won't definitely do that with a xDSL connection as usually this is asychronous having a high download rate and a much lower upload rate. It simply makes no sense if your upload is for example 1 or 2 MBit and you limit the connection of the VPS to 100, 10 or even 1 MBit after x amount of traffic.