Parts are expensive. To save on costs, we usually buy our parts and materials in bulk. However, due to inflation, as gas prices fluctuate, so do the costs of parts, overhead costs, and cost of living wages. Unfortunately, the costs of parts usually go up and rarely go down in price. Sometimes a year or two can pass without the cost of a part changing much if any. Sometimes they go up every few weeks. When the price of materials goes up we have to adjust our prices to cover our expenses. Most likely, if you paid a certain price for something 5 years ago, it will not be the same price today.