That quote is taking the pee. All of the BeyerDynamic phones are designed for easy replacement of any of the parts.
I'd order a replacement cable like this for under a tenner: https://amzn.to/3PHXgHt and DIY it.
Here's a how-to:
If you're handy with a soldering iron it should be easy; if not, you might have a Basschatter near you who'd do it for a pint.