Platinum Micro via eBay offers the HP S700 120GB Serial ATA 6Gb/s 2.5" 3D NAND Internal SSD for $38.99 with free shipping. That's a buck under our mention from two weeks ago and the lowest price we could find by $7, excluding the mention below. It features read speeds of up to 550MB/s and write speeds of up to 480MB/s.

A close price: Walmart has it for $39.99 with free shipping.