Yep no doubt , the 6600GT is an excellent buy, its better than the 9800pro/xt, the XFX 6600GT AGP costs about 14.4k and the PCIe counterpart costs about 14.7k.
However, one card I think is going to blow away the 6600GT, if priced rightly is the ATi x800xl, it even beats the 6800GT in some of the reviews I have read. The card is currently available only in PCIe, but there are chances of the AGP variant being released sometime in Mar-April 05. The card has been released to capture the mid-level market, and capture it will if priced competitively. Infact its suggested MSRP is supposed to be US $100 lower than the 6800GT and the x800Pro. Also there is the plain vanilla X800, which should also be better than the 6600GT and having a suggested MSRP of US $ 199 .
This is how the X800XL and the x800 stack up in the entire X800 Series -
Chip--Pixel Pipelines--Graphics Core--Frequency--Memory Frequency
Radeon X800--12--400 MHz--350 MHz
Radeon X800 Pro--12--475 MHz--450 MHz
Radeon X800 XL--16--400 MHz--500 MHz
Radeon X800 XT--16--500 MHz--500 MHz
Radeon X800 XT PE--16--520 MHz--560 MHz
I was planning on going in for the 6600GT, but I think I'll wait, I'll be getting the rates for the x800 and the X800Xl maybe by the end of this week, I'll keep you folks posted.