Amazon offers Prime members the Crucial 8GB PC3-12800 DDR3-1600 SO-DIMM Laptop RAM, model no. CT102464BF160B, for $25.99 with free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping costs $8.) That's $2 under our mention from three weeks ago and the lowest total price we've seen. (It's also the best deal today by $7, outside of the mention below.) It features a CAS latency of 11.
Of note, Newegg Business charges $24.99 with free shipping.