I actually ordered this exact same dock but from a different E-Bay seller, and mine came with a total of six items for $25.48 including shipping!
It comes with:
1 x Horizontal Dock With Spare Batter Charger Slot
1 x Spare Battery
1 x AC Power Adapter (US Standard)
1 x Free Mini USB To Micro USB Converter
1 x Free Retractable Stylus
1 x Free Screen Protector
It ships from Hong Kong and the posting says its does NOT work with the US HTC G2 model, but I don't see how that's possible since the Desire-Z and G2 are built identically.
For all this, the Buy It Now price was/is $19.99 + $5.49 shipping. For that price I'm willing to take the chance. The seller has a 98.3% positive feedback rating from 35,864 feedback postings.
The only thing I'm not too thrilled about is that, according to the posting, to charge the phone and the spare batter you have to have the AC adapter AND the usb adapters both plugged in. But that really this a big deal.
That being said, I ordered mine on December 3rd and it shipped December 4th (from Hong Kong). SO I should be receiving it sometime this coming week. I'll report back once I have it on hand.