Kiler deal on a telephoto lens?

[river251]

This telephoto lens:

2X TELEPHOTO LENS FOR CANON POWERSHOT S3 + TUBE ADAPTER - eBay (item 110358589168 end time May-26-10 05:52:36 PDT)

has about the power of this lens (first one):

Raynox accessories for Canon PowerShot S5 IS, S3 IS, S2 IS Digital Cameras

The obvious physical and price differences must mean the cheaper one will not do what the more expensive one will do. What is probably lacking in the first lens?

Thanks very much for any enlightenment for this beginner, I'm using a Canon S3 IS.

Jim