Lexus parts can be expensive, since they’re intended to be used for a high-end, luxury vehicle. However, a well-maintained Lexus is generally cheaper to maintain on an annual basis than less luxurious vehicles because of the quality associated with the luxury brand.
In general, that means each repair might cost more to complete due to higher part prices, but if you’re responsible with your vehicle, you should need to pay for repairs less often overall, bringing the cost of maintenance down.