Whenever purchasing RDRAM kits off of eBay, there's a few things to look out for to avoid getting scammed.

Some sellers often times list memory as new when it is really used.  How can you protect yourself?  Nearly all RDRAM modules ever made have the year listed on the label:

• Samsung: The year can usually be found in the upper left of the label in a two-digit format (ie. '99' or '04').  So if you have '0326' in the upper left then the chip was manufactured in 2003.
• Elpida & NEC: Look at the string of numbers and letters at the bottom left.  If you have '0243SX5501' then the manufacture date is 2002.
• Kingston: Look at the string of numbers on the bottom left.  The first two digits indicate the year.  For example, '9930165-002.A00' indicates a manufacture date of 1999.
• Infineon & Toshiba: These modules usually do not have any date indication.
• And when in doubt, check the manufacturer's website.

-All new memory should be sealed, unopened, and in perfect condition.  If it isn't you should be very skeptical about your purchase.

A seller is listing RDRAM with a lifetime warranty.  Does it really have a lifetime warranty?
-Unless specified that the seller themselves is offering the lifetime warranty (and not the manufacturer), RDRAM does not come with a lifetime warranty.  There are four exceptions to this case though: Corsair, Edge, Kingston, Simpletech, and Viking.  These four companies offer lifetime replacement warranties on all of their memory.  Samsung, Elpida, NEC, Infineon, and Toshiba modules do NOT have a lifetime replacement warranty through the manufacturer.