E46 N42 automatic Flywheel ( What are my options)

Hi guys
My cars a 2002 E46 318i N42 Automatic .

So I have been getting this odd tinny rattle noise on my E46 when ever the engine is on and the car is moving up or parked at a slight incline for some time now.

BMW suspected that its the flywheel thats the problem . They tell me that with age the welds break loose and separate from the main wheel . ( I dont know how true this is , I know nothing about flywheels)
I took it to a reputed transmission place and they told me the same thing .

My gearbox has never been separated from the engine , its never been taken off the car . They tell me its an age related thing. My Milage is now at 265 000km

What are my options?

Is a new one from BMW my only option? Its so pricy .
Im afraid of a second hand part as I fear the same might happen and the labor cost is not cheap for replacing this piece . Are my fears unfounded?

I was told that it can be rewelded as well but then again , I was also told that those welds might come off and these parts need to be properly balanced?

Do I have any other alternates? are there any other reputed company's that sell these pieces besides new from BMW ?

Im also told that I should not just let anybody do the repair as this part needs to be properly torqued in to the correct setting as if its not , it will crack again.

Gears and everything seem to shift fine.

What should I do?

Thanks guys for all the responses . Heres a picture of the part in question that I pulled of the net .