We all like to save a little money where possible however sometimes the cheapest option may not be the best in the long term. Spare parts are by definition an interchangeable part to replace an original that is at the end of its useful life.
Some spare parts are designed as consumables meaning that they are non repairable. A good example of this is the average car tire. Once the tread is gone, the tire is no use. However it should be noted some tires are remoulded with a fresh tread glued onto them. The problem is that remoulded tires are not as good as the original, sometimes the tread can peel off, they do not have the same speed rating and are a classic example of why sometimes a cheaper spare part is not the best choice.
Other spare parts are repairable and can be exchanged for a reconditioned unit. Some car parts such as alternators, starter motors and sometimes household items such as washing machine motors can be exchanged in this fashion for a refurbished unit. Computers are a very popular item for refurbishment with many companies offering good deals. These usually come with a guarantee however it is for a shorter time than a new unit which means that although you save money in the short term, in the long term if there are problems with the refurbished part you could end up losing money.
Using high quality spare parts relieves you of these worries as they are generally made to a higher specification and tighter tolerances meaning that they last longer and in some cases even fit better. Generally, high quality spare parts cost more to buy but this is offset by the long guarantee many parts have and the much longer lifespan that they have in use. In conclusion, using high quality spare parts will save you money in the long term and help alleviate any worries about possible future problems from the same source.