Upgrading RAM (Budget)

I currently have this RAM in my system; SAMSUNG 8GB 240-Pin DDR3 SDRAM ECC Registered DDR3 1600 (PC3 12800) Server Memory Model M393B1G73DB0-YK0, and i was wanting to get another 8 GB installed, but the question is is there any cheaper alternatives than buying the exact same ram stick that is equivalent in speed and compatibility?