See bottom of post for update.
Anthropologie's Double Torsade necklace retails for $28 and comes in two other color combos.
It varies some (in the color for one, and these are chains instead of beads), but this half and half necklace from Charlotte Russe definitely has an inspired by style for a much lower price. This budget friendly necklace retails for $8.50 and you can click on the photo below to purchase.
*Update - 7/29/10* - A couple of readers have pointed out that since I wrote up this post, Charlotte Russe has added a great (very close) lookalike to the Anthro version for $10.50. Click on the photo below if you're interested in purchasing.