Whenever you have some kind of device that breaks down this often means you would bring it into a repair shop because it’s not like you know how to repair the thing. If it requires new parts usually the service provider has these available and would add it on your repair bill. I often find that the parts you buy from repair shops can sometimes have extremely inflated prices. This is often due to the fact that the customer has very little knowledge in the area and so they just assume that’s how much I t costs normally.
What I find useful at times is if I know what is wrong where it is a parts replacement I would research ahead of time in regards to the cost of the item. That way, I can either buy it myself and bring it into the shop for repair or with the research I have done I can ask the business to essentially price match the item where people often don’t want to charge over inflated prices when they see another place selling it for way cheaper.
If you have no clue what that item may be you should be told by the service provider on what needs to be replaced specifically. From there you can use that information to research the price of the item to see if it is a good price or not.