Corsair 4 GB DDR3 Laptop Memory Kit CMSO4GX3M2A1333C9 for $76.46 shipped on
Amazon
4GB (2 X 2GB) DDR3 Laptop Memory Kit - 1333MHz Unbuffered CL 9 SODIMM Memory
9-9-9-24 1.5V
Link: http://www.amazon.com/Corsair-DDR3-Laptop-Memory-CMSO4GX3M2A1333C9/dp/B002YUBVES/
It has been posted at higher price before. I think that it's good price as
other 4GB DDR3 SODIMM kits usually go for around $100. It seems that this
kit works fine for Macbook Pro according to some posts.