Depends on your history. If you have been riding for a while and know that a KLR650 dual sport is what you want, then you can get a new one and break it in and fit it out as you want. You will know personally where every scratch and ding came from.
If you are new to riding, you might want to get a used one for a lower investment. You can learn about dual sport bike and dual sport riding. You may learn that you like street bikes better or bigger or smaller or that you don't really like motorcycles as much as you thought you would.