These things are important but it is more important to evaluate other ATV parts. These are not just any parts but performance parts. For the body you could easily bargain and ask for a cheaper price. Mostly people purchase a good looking ATV and purchase second hand performance parts. This is not a wise choice. You could easily purchase second hand body parts, spend some more money on it and it would be as good as new. You can go over the internet to find better rates. Going to a dealer would not be wise. Performance parts on the other hand do not work like that. These parts wear off by time and need to be replaced. Purchasing such ATV parts second hand would only cause more trouble in the future. As a second hand part is worn off.
The best way to purchase performance parts would be to buy them at wholesale. This way you could purchase more of them and at a lower rate as well. These would not go to waste as you would need to replace these when your existing part wears out. There are some performance parts which do not wear off. The engine is a great example. Purchasing them at whole sale would do you no good. Try to sell off your engine and add money to it to buy a new one. If that is not possible then buy a new one. Be sure to install new ATV parts in the engine not second hand ones.