Adata via Rakuten offers its Adata Ultimate SU800 3D NAND 2.5" Serial ATA 6Gb/s Internal SSD in several sizes from $48.44 via coupon code "ADA15", as listed below. Plus, these orders receive free shipping. That makes each of these either tied as the best we've seen, or the best price outright. The deals, with prices after coupon: 512GB for $48.44 ($9 off) 1TB for $84.99 ($15 off) 2TB for $178.49 ($32 off)
One grocery chain is likely to save you more money than any other.