If you've only had the printer for a month you should not need a new printhead - call HP support and perhaps they will supply a new one. I've had mine for almost a year and done quite a bit of printing and only replaced one so far.
Printheads are $46 at Provantage.com...
I've had it since May of 2007. Printheads say they are still in warranty through Sep. 2008.
Is it worth trying to get HP to replace them, or should I just buy them? Looks like I need to replace Y-M and GE-G.