I heard nobody recertifies belts. They re-web them. Your hardware with new belts.
I use the RCI Platnum series. They will reweb them 1 time for free. So it's kinda like being good for 4 years instead of 2. It cost me about $12 to ship them to them and I think it was $20 shipping and handling to get them back. Basically $32 for a new set.