I would recommend your activity and needed to furtherly mention that Dell manufactured my Alienware machine as it is under their umbrella of Branded PCs, it is first class for the portability and sheer quality of hardware PLUS sheer rapidity now I have SSD (solid state disk drives) fitted. The SSDs are two 1Tb solid state disk drives. That had made the Alienware (DELL) machine RAPID!!!!!!!
Crucial RAM is guaranteed to work in Dell's and has a lifetime warranty.
If you want to save a little on a somewhat older machine, I use A-Tech RAM, which also has a lifetime warranty.
Kingston Value Ram (KVR) rarely works in Dell's.
If you find Crucial RAM at a lower cost on eBay, that's because it's used.