Carpet negotiation and where to buy

[Bryan N.]

I saw this post

http://www.biggerpockets.com/forums/52/topics/6908...

@kimberly S. mentioned negotiating the price, because it's like buying a car.  

For negotiating:

I'm assuming go to local stores (not box box or chain) to get quotes, but what are you successfully haggling?  Is it the price, the install, or the dumb stuff like tack strips etc...

For where to buy:

Big box, local, Craigslist, Angie's list, or somewhere else?

Thanks in advance for any advice.