So far I have spent a total of absolute zero on headphone cables for any of the dozen or so pairs of headphones I own, I use the one that came with them.There is also an argument to be made for peace of mind. I use quad star XLR cables for my power amplifiers. Probably makes no difference compared to non quad star in terms of noise, but I just wanted to be sure it would never be an issue. So I spend €20-25 on a cable instead of €10. But I would never do the same if the difference was €10 vs €100+.
However inexpensive a different cable is it is a waste of money IMO.