That is true. However, those less performant chips, due to the way NAND storage functions, could easily be used in place of the newer chips. If you need twice as much performance, you just use 2 chips and you're done. Unless dealing with extreme size constraints like in a cell phone (where the high-performance NAND isn't even used for price reasons), there's no real reason to prefer a single chip over two. For the consumer, that is. If you're producing chips and trying to drive per-chip profit margin and trying to make your product look like CPUs and other products that have some complexity behind them, though, it's useful.

I can understand how NAND prices don't look suspect if you're not terribly familiar with the history and low-level factors of the industry, but if you really look into it, it's kind of ridiculous. The same companies price-fixed DRAM chips and got busted. Then they price-fixed LCD panels and got busted. Then they price-fixed DRAM chips again and got busted again. They were being investigated for price-fixing NAND chips, but the South Korean president shut down the investigation. Shortly before being ousted for rampant corruption (and then being bailed out of prison by Samsung). Anything that is present in such a gigantic variety of devices should cost almost nothing. That's just economics. It becomes commoditized. The materials involved and their rarity become the primary drivers of price. Comparing price per terabyte of storage between mechanical drives and NAND-based storage is the most telling to me personally. The technology that goes into modern high density mechanical hard drives is utter madness. They should be, by all accounts, astronomically expensive. They use helium, of which there is a global shortage. They coat the platters with rubidium and other rare materials. They include neodymium magnets. They include high precision mechanical motors that spin platters fast enough that the surface tension against the air becomes a significant factor (leading to the use of helium) and still maintain enough precision to be able to seek to a very precise spot in nanoseconds. Also, you've got 'hybrid' drives that include both the mechanical and NAND storage... which incurs almost no premium over the pure mechanical solution. Now they're beginning to produce drives with integrated lasers for heat-assisted magnetic recording. And these are still many times cheaper on a $/TB basis compared to.... just a dumb parallel array of NAND gates that don't require anything rare?