Pretty much everyone offers some "free" shipping these days, which is just a marketing scheme anyway. Free shippoing or not, the only number that matters is the total, all-inclusive price. It's not uncommon for me to find a lower total price at a seller that charges for shipping than the Amazon's "free" shipping price.

WSJ actually just published an article on how Amazon is frequently underpriced by other sellers: http://online.wsj.com/article/SB2000142412788732342380457902...

There's no one seller that is consistently the lowest price. But Amazon is consistently the slowest in shipping.