Brake discs from the bay?

Good day, since my brake system gives noise when driving squeak and the brake disc has been in use for more than 190 tkm I would like to make a general overhaul of the brake system. I was not really shocked by the prices for the material but nevertheless I noticed something: spare part Dealer of my trust: brake discs: 120€ brake jaws: 40€ Toyota Workshop: brake discs: 180 € brake jaws: 110 € eBay: complete set is already available from 40 – 80€ I mean between the dealer and Toyo workshop I can still understand this halfway. But the bay costs just half the set for 80€ or only a quarter of the set for 40€ But what can be kept from such eBay offers? If I buy such a cheap set I save “a lot” money but is the performance of the brakes equally good? or even better? No one would like to look for such a cheap set just look for “Bremsscheibe Corolla E11”. Buy junk that can’t slow me down from 200 to 100 km/h if necessary. Have you already had experience with such eBay offers?