The trouble is its Ebay, its second hand. I notice the seller has 100% feedback so far and thats good. I personally wouldn't buy second hand memory but many people do. Is the memory any good? Well yes its ok the Value range is the cheapest memory Kingston do. But the memory has to be compatible with your system you can't just bung any memory in and expect it to work. If its the wrong memory and you buy it will they refund you?
Pixmania I would never buy from in case something went wrong as its based overseas, France I think and if anything goes wrong it means you have to post it overseas.
I know its dearer but you can't beat Crucial click here and if you're unsure of what memory your PC can take then look here even if you're buying elsewhere.