Buy.com via Rakuten Shopping offers the Samsung 850 Evo 500GB Serial ATA 6Gb/s 2.5" Internal SSD, model no. MZ-75E500B/AM, for $197.99. Coupon code "SAMSUNG45" cuts it to $152.99. With free shipping, that's the lowest total price we could find by $24, although it was $3 less a week ago. It features read speeds of up to 540MB/s and write speeds of up to 520MB/s.

Of note, enter coupon code "REWARDME" to yield 765 Rakuten Super Points. (They convert to a $7.65 Rakuten Shopping credit.)