I don't know what sort of price this cable was, but I do assume that it likely was around double or more than the headphones, which I certainly can't see the point of, but it is a personal choice.
What however baffles me is how a cable of this cost can be worth it when it only goes into one side. It's still got to go through the stock wire to the other driver, which is thin and cheap cable. Statistically speaking, if doing measurements now compared to before, these headphones will now be more unbalanced than with the stock cable if this premium cable makes such an improvement. To make the most of an upgrade like this at this cost, I would have thought that it would make much more sense to have it going directly to each driver to make it completely balanced (personal view again).
I made the cable myself for my AKG K550s. The parts were around £20 in total and also will likely be a "marginal" improvement over the stock DT880 cable.
I manufacturer many full size XLR cables in my workplace now and some 6.3mm jacks too. I personally am starting to become unconvinced about how these other cables that nearly cost £1000 can be worth it. Seeing the description on lavricables site stating that your devices should have 150 hours of burn-in time before serious listening baffles me. I would say the products shouldn't come out of the factory if you must leave noise playing all day and night for nearly a week before you can do archive serious listening..... I just hope they don't mean it helps the cables improve too!
Sorry for the rant!