O2 Sensors are expensive!!!

I have an '01 Stratus R/T and low-and-behold just as my warranty ran out, I found out that I have to replace one of my downstream (after cat) O2 sensors. While I'd just rather deal with the light since its impact on fuel economy is zilch, I'd like to replace it. Can anyone tell me where to find an affordable replacement? Advance wanted to charge me $180 for the freakin sensor. Then I went online and saw that they would even sell it to me online at $155. I figure that I've got to be able to find this thing cheaper. Preferably with wiring.

Any suggestions?

I wish, i one of my o2 sencer cause about 120 for my alero. Look at autozone.com
www.carparts.com
Hope this helps on price.