Has anyone heard the new Eric Alexander signature speakers the matrix LS?

Yes, that is the SB Acoustics Beryllium tweeter. I have now used it three times in an evolving design and it is my new favorite tweeter supplanting Aurum Cantus ribbons and Scanspeak silk domes. They retail for $470 each. In quantity I am sure Eric's discount is healthy, but no more than 30% in this environment. 

They may sound good but $18K, and you get those same  DIY looking cabinets with woofers that aren't flush mounted? Fail in the aesthetics column.

$18K should buy beautiful sound AND looks.

Yes. And it does. On Planet Utopia. The Nowhere land where everyone flies to work on a unicorn and Coca-cola comes out of every faucet. $18k should buy me a beautiful speaker, beautiful car, and three beautiful women. A house. And beautiful wife to clean it. Should is my favorite word in the English language. So infinitely useful.

Meanwhile, back on planet Earth: Functionality is what it's all about. Sound quality. The most sound quality for the money.

You can have your Faberge Egg. You can even tell yourself it sounds good. For $180k it should sound as good as the $18k Tekton. There's that word again. It should.

Good luck with that.

Pricing seems excessive? Replace standard tweeters with Beryllium and a few other changes, but keep the DIY appearance/build?

Eggxactly predictable.