ADATA’s eBay store has a couple of their top-rated 512GB SSD drives on sale for only $64.99 each. Get either the XPG LITE SX6000 Series: 512GB Internal PCIe Gen3x4 (NVMe) Solid State Drive or the ADATA Ultimate Series: SU800 512GB Internal SATA Solid State Drive.
Depending on your application or needs, you can’t go wrong with a half terabyte of fast solid state storage for $64.99.