There's a big difference between Samsung's 990 Pro NAND and controller chips (TLC NAND, DRAM acceleration, and a good controller), vs. bottom bin flash storage.

There's a big difference between Samsung's 990 Pro NAND and controller chips (TLC NAND, DRAM acceleration, and a good controller), vs. bottom bin flash storage. It could be used QLC (4-bit per cell) NAND with no DRAM and a much, much worse controller and still have 2TB of space. For context, actual "real" low-end NVMe drives are 2TB for ~$180. The Samsung is $300 for 2TB right now. I could easily see you cutting cost by using used NAND and horrible controllers and get a cost much lower.