The tax for R Plates is Naf312.50, which isn't much more than regular M Plates which is Naf287.50. What I'm sure is expensive is the number of plates they must buy, but if you are running a business, you should plan for that expense and have the plates changed out when you are supposed to. Now, if you have diesel car or truck, those charges are very expensive. The tax I noted is for gasoline cars.