Used truck parts are much more affordable than new parts while providing the same results. Plus, the market for recycled truck parts offers a huge selection, so finding the ideal parts you need is easy. There are three ways to approach the used truck part market: 

OEM Parts: OEM or Original Equipment Manufacturer truck parts can be new or used components that were produced by the same truck manufacturer. So for a Freightliner truck, you can get Freightliner parts, guaranteeing that your OEM part fits your truck perfectly. The truck parts themselves are certified manufacturer quality based on the source and the production methods used.

OE Parts: OE or Original Equipment truck parts, also come from the same manufacturer that built the truck. The difference is that they are less costly because the manufacturer subcontracts the production of the truck parts and oversees assembly. OE truck parts offer the same level of quality as OEM parts.

Aftermarket Truck Parts: The cheapest way to go, and one that is more accessible, is aftermarket truck parts. These truck parts are not assembled by the manufacturer in any way but they fit and last just as well as OEM parts. Aftermarket truck parts are exact replicas of the OEM parts that were originally in the truck. They can be purchased new at much lower price points as several manufacturers take part in the process. These truck parts can be readily found at many dealers.
It's difficult to do any better than aftermarket truck parts due to ease of access, reliability, durability, and excellent quality on top of their cheaper price tags.