On my most recent rummage through the bowels of eBay, I found an interesting listing for various CCBS limbs. eBay has been slowly but steadily evolving, it would seem, and now allows sellers to make a shop for multiple items out of one listing.

What I found impressive about this seller was not just the variety of parts available on the listing, but their courtesy in listing sets the parts came from, as well as the part numbers, which you can easily cross reference with BrickLink. Their visual guide also aides in this process significantly.

Some of their parts do come up more expensive than averages on BrickLink. However, they do include instructions on combining multiple purchases which may actually save you enough on shipping/fees to beat out some of the BrickLink competition.