I'm sure the DIMMS sold in these ebay links are fine and the seller does have a good rep as someone above mentioned. I'm weighing if I want snatch four of these up on ebay or if I pay approx $50-55 more per dimm from a place like wiredzone.
$289.99 on the Samsung's which is only a $0.45 price drop.
@BennyT $50 more per DIMM versus this is silly. I've bought from the Samsung seller before and the modules look either new or like they are being pulled from new systems.
The mem-store is a bigger risk but they've got over 23,000 feedback on ebay at 99.8%. If their stuff didn't work, no way they'd be able to keep that high of a rating on their modules. I'd pay $289 for the Samsungs over $280 for the mem-store, but not $50 more.