eBay and club members speak two different languages when it comes to rarity, to wit:

eBay Sellers vs Official Price Guide

Uncommon = R-1 thru R-3
Scarce = R-1 thru R-3
Rare = R-1 thru R-3
Very Rare = R-2 thru R-3
Extremely Rare = R-3
Unique = R3 thru R-5
No Equivelant = R-6 thru Unique

In many years cruising eBay, and over 3,000 transactions, I have NEVER seen a chip described as Extremely Common, Common, or Fairly Common. I have often seen R-1 chips described as Rare. In fact, Rare seems to be the most common availability of anything on eBay, except by some trustworthy dealers, most of whom are members of the club.