Spare parts prices

Hello dear engine talk community! As a driver of a relatively rare car (Opel GT K/R) you are used to the fact that the prices of spare parts were often quite … imaginatively calculated. But what happened to me now is simply the hammer!! I want to change the transmission oil and therefore go to the friendly Opel dealer to get the necessary sealing rings for outlet and filling screw (can be nothing wild, are only small things). On the other hand, the price literally catapulted me out of the door: Adam Opel AG would like to search for an aluminium seal ring (see picture), which is available for about 6-10 cents outside, say and write 56 euros!! (If you don’t believe it, just do your own research: part number 89048245) I wrote a friendly letter to Adam Opel AG (see appendix). I was curious if a meaningful answer was actually written. or just a form letter comes… I’ll keep you up to date! I then got the necessary sealing rings via another GT driver who imported the parts directly from USA. (Before now some start “Then buy somewhere else!”, “Self to blame, what was driving so much prolcarry” and similar friendlinesss: I like the car, I’ve already got many, many parts from various FOHs, even if the prices often gnashing with the teeth, but that’s what I’m looking for. Has something like this happened to you before?