We have an older bad boy buggy. The number one question I would ask is do you have steep terrain. If you do, the old ones are horrible. They did not beef the brakes on the earlier models, which you would be looking at for six grand. Get them going down a steep hill and watch out. They will push through the electric braking and slide and do all kinds of things except stop. Keep it on fairly flat ground, and it is a great vehicle. It sucks to have to pay six or seven hundred bucks to change batteries, but how much gas would you have purchased in that time with a regular machine? It depends on use I suppose. Anyway. flat ground....great. Steep hills? Never again.
I also, in fairness to them, think that newer models have MUCH better braking systems on them.