Samsung recently announced mass production of a 30.72TB SAS SSD, the PM1643. The drive combines "32 of the new 1TB NAND flash packages, each comprised of 16 stacked layers of 512Gb V-NAND chips".
There's no word on price yet, but if we go by the street price of the older PM1633a 15.36 TB model, at around 8000 USD, then expect doubling in size to mean at last doubling in price as well. At 16000 USD, thats 53 cents per GB. Currently, spinning HDD is about 3 cents per GB, and the cheapest SSD at around 30 cents. A 75% premium for an enterprise SSD over the consumer options is perhaps not too unreasonable. However, 17 times more expensive than a HDD will not scale in the data center. In comparison, four 8 GB WD Red drives will give higher capacity and cost about 1075 USD.