I think there will always be a market for those labels. Yes, people wise up, some sooner than others, but there are always newbies coming along that think they are getting better quality with ER or FR labels. If they are willing to pay, who am I to refuse to sell?
I'm not sure they add any value. I have slabs with/without signed labels and I pay the same price. which means they sold the same. I wont pay extra but I guess some will. I don't think you can count on it.
OK, for you there is no added value in those labels, but for others, those labels do add value. I have found that many actually will pay more for FS/ER labels. You won't pay extra for those labels so you are not the customer I seek, nor will I change the way I sell to please your tastes.
People have paid good money to buy a corn flake shaped like a religious figure. With 6 billion people in the world, you can find someone for anything.