Well, in all politeness, when you become someone who makes something that hundreds of unwashed black shirt wearing weirdos* pay extra to attend a show early just to buy you out of everything you brought....you'll be free to conduct business however you want, ya know?
God, I can't believe I'm having to defend a bum like Burger, but the fact is, dude was only taking cash that day...and sold all his knives that morning, it sounds like. I'd daresay he's not too bothered by any potential business lost from someone who came to BLADE without
cash.
Sorry, I have to laugh, because I'm just trying to think on all the sweet deals I've made at BLADE in all the years I've been going because I had cash in hand, and I can't even remember 'em all. If you show up to BLADE with only plastic in your pocket....you're just kneecapping yourself unnecessarily, in my long, direct experience. I've been going to BLADE as long as OP has, all that time cash has been king.
* I'm a washed version of this exact weirdo, so I get to make fun of my own tribe!