900$ wat a rip-off! I bought mine last week from
http://www.clove.co.uk/ for $636.00AUD (including delivery to sydney australia!)and the HTC Desire Z is for $582.54AUD on their website.
Also you can also check out
http://handtec.co.uk/ for nearly the same price.
Both website are selling the unit unlocked.
Here in sydney it's for 800AUD, I reviewed it on the weekend from vodafone, and the phone is gorgeous! it's amazing how snappy it is. I used to hate HTC Sense, other skins on Android, but the new HTC Sense and its themes are real snappy. You can definitely feel the difference with the 768 MB of RAM.