With "just" 840MB/s and 100K IOPS, it really shouldn't be expensive - at least no more expensive than current SSD prices of about $1 per GB. I am wondering though if simply striping two decent SSDs won't be about as fast - or faster.
Now this dude (Samsung XS1715 NVMe), with 3GB/s transfers and 740K IOPS, is probably seriously out of my price range. Any guesses how much will this one cost? ("if you have to ask, you can't afford it"? :))