What you need to know is that these are just tricks to make you think that. Sure these parts are cheap, but they might just cause damage to other parts of your vehicle. Another thing is that these parts have quite a short life. This means that when something big comes up you would probably be unaware of it. The reason is that you would be satisfied that you have replaced the performance part only recently. These are only a few of the problem caused by replacing performance ATV parts with a second hand part. Purchasing second hand parts is not something bad. You just need to now which parts should be bought second hand.
The most important thing which you need to know is that performance is important than looks. Rather than wasting money on brand new body parts it would be best that you use that money to purchase performance parts. Body parts can be bought off second hand. These might look in a bad shape and in a different color. But that should not bother you. All you would need to make sure is that whether they fit properly on you vehicle or not. After that you would just need to get these ATV parts get treated for dents and then painted; this would make them look as good as new.