I went looking for a low price peltier cooled ccd camera a while back and found the ATiK. I've carried out a few measurements with it as far as response curves, linearity etc and it came up pretty good for a sub $1000 astro ccd camera. Compared quite favourably with some of the more expensive cameras actually.
http://www.astrovid.com/prod_details.php?pid=3246
With the Aussie Dollar trading so well atm it comes in at a very reasonable price.