Mark doesn't set the price of these guitars! It is only expensive if they don't sell, but the fact they do sell means people are buying them at that price. There are still plenty of other cheaper guitars to buy. The fact it has the name Mark Knopfler on it, naturally makes it more expensive. This is all clever marketing for the guitar makers, and good luck to them; for Mark it must be a thrill to have his name on guitars he fantasized about when he only had his first £50 guitar, I know I would be.
I'm sure he's thrilled! But I won't say that the fact that guitars sell well justifies everything, people would buy even a toilet paper as long as it would have Mark Knopfler name on it. Mark has a lot of rich and loyal fans who can pull the trigger on anything with MK connection, so guitars would sell even with 10X price, it would just take a little longer.
There's a question of psychology also, who's the end buyer of an MK instrument? Surely a guitar collector is exactly a kind of guy who can buy some MK instruments, because it's a 'good investment'. But MK is not a collector himself. A professional musician? I think he would build a guitar to own specs, rather than relying completely on somebody else's, I've never seen Mark playing on an Eric Clapton signature strat. But surely a lot of MK die-hard fans are 100% confident that Mark's specs are the best specs in the whole wild world.
So it leaves only a tiny little fraction of actual genuine fans, who just love good guitars and not necessarily professional musicians, but the fraction is nothing on the grand scheme of things. Most of the guitars has gone to the collectors and rich people, not exactly inspiring in my book.
Coming from the guy, who said hundreds of times that he loves cheap guitars, and started on cheap guitars, selling 3-5-10 grand guitars is kind of strange... To me. If his ego can't stand putting his name on a cheaper instrument, why even bother because of the above? And all he can say: I'm sorry buddy, you don't have enough dough, come back next time.
I'm not a fan of all this signature thing, and I figured even if I had enough dough, I would go with a cheaper alternative without MK tax.