Scroll to the bottom of the page on Scan: it's verified by McAfee, Verisign (Symantec), Mastercard, Visa, and complies with RoHS. You can also use any secure payment method you want, whether it's credit card or PayPal (which would probably be what you're using on eBay).
Lol Ebay is not more secure. If anything it's worse considering since they became butt buddies with Paypal they just screw people over. There is like no seller protection anymore.
Yea Scan is extremely reputable, while Ebay IMO is a total pile of crap but hey like I said before to each his own. If he gets his RAM safe and sound I suppose that's all that matters.