I got mine in my React Cooler kit, included is a HDMI cable, the Audio converter, a play and charge kit, and a optical cable (for audio), as well as the 3 fan (in power) cooler unit, as well as the rechargeable battery pack for your controller...
Got mine off ebay for $17 ish dollars. Lemme link what it looks like...
and so far- no issues with the React cooler...
React RT1200 Starter Kit for Xbox 360 - eBay (item 160327202685 end time Apr-15-09 15:07:03 PDT)
That is also the buyer I got mine from, which I rated 5 star.
So since I got mine for around $20, the play and charge kit alone is that much (with battery) The only thing I don't like is the play and charge kit has 2 LED's Green and Red- and are both insanely bright when on (plugged in), so you might need to take a marker to them to dull them down.
All I really wanted was the Play and charge kit and rechargeable battery for my system, but saw this deal and figured why not? extra parts could be sold cheap to people that need them, and the HDMI cable isn't bad quality either, I believe it has the gold plated connections and everything.
Just FYI on prices here:
6ft of HDMI cable $10 (Newegg)
3ft of Audio Optical cable $5
Play and charge kit $20
"Intercooler" fan $25
Audio Converter $15
Yes it is not "microsoft genuine" but I really haven't heard bad things about the brand "React"