Newegg
500GB HP EX900 M.2 PCIe 3.0 x4 NVMe 3D TLC NAND Solid State Drive (2YY44AA#ABC) $49.99 + Free Shipping
https://www.newegg.com/hp-ex900-5…6820326251
512GB HP EX950 M.2 2280 PCle Gen3 x4, NVMe1.3 3D NAND Internal Solid State Drive (5MS22AA#ABC) $59.99
https://www.newegg.com/hp-ex950-5…6820326205