Cheapest RAM I Could Get?

I want to see what is the cheapest RAM anywhere. I want 16GB on my Satellite P845T. Here are my specs:


DXDIAG:

System Information
Time of this report: 5/12/2013, 22:32:29
Machine name:
Operating System: Windows 8 64-bit
Language: English (Regional Setting: English)
System Manufacturer: TOSHIBA
System Model: Satellite P845t
BIOS: 6.50
Processor: Intel(R) Core(TM) i3-3217U CPU @ 1.80GHz (4 CPUs), ~1.8GHz
Memory: 4096MB RAM
Available OS Memory: 3998MB RAM
Page File: 3717MB used, 4526MB available
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TECHSUPPORTGUY:

Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 8, 64 bit
Processor: Intel(R) Core(TM) i3-3217U CPU @ 1.80GHz, Intel64 Family 6 Model 58 Stepping 9
Processor Count: 4
RAM: 3997 Mb
Graphics Card: Intel(R) HD Graphics 4000, 1806 Mb
Hard Drives: C: Total - 466491 MB, Free - 399097 MB;
Motherboard: TOSHIBA, TOSHIBA
Antivirus: Trend Micro Titanium Internet Security, Updated: Yes, On-Demand Scanner: Enabled