newegg Business offers the Crucial M4 512GB 2.5" Serial ATA 6Gb/s Internal SSD Solid State Drive, model no. CT512M4SSD2BAA, for $399.99. Coupon code "MEMKMYTEN" drops it to $359.99. With free shipping, that's $0.70/GB and the lowest total price we've seen for a 512GB SSD by $36. (It's also a current price low by $57.) It features read speeds of up to 500MB/s and write speeds of up to 260MB/s.

Of note, you will need to provide a Tax ID number to create an account and purchase this item.