Many people feel that to get the best deal on car parts that they have to go second hand. However this is just not true, if you look in the right places you can often get new auto parts at prices that are the same as those second hand ones. Online stores are a great place for cheap car parts, one reason for this may be because they don't have expenses from advertising and bricks and mortar stores. Also if you check around the online stores you can often find the part you are looking for on special at a really discounted price.
You should also not rule out refurbished car parts. Many people write them off because of the fact that they have been used. They may have been used but since being taken off their previous vehicle they have been inspected and brought back up to a good standard. Many people don't realize that reconditioned auto parts often come with a warranty or guarantee. They are also at the middle ground when it comes to prices because they are between new and used parts.
Wherever you purchase your cheap car parts, you should ensure that they are the right part for your vehicle. The store should be able to answer any of your questions regarding compatibility with your vehicle. Online stores often have a parts checker so you can be sure you are getting the right part for your vehicle!