Nitty Gritty of credit and debit cards

Here's an interesting piece on the behind-the-scenes costs to retailers and to you of using credit and debit cards.

- @0.7% of purchase price is a fee
- 1% to 3% interchange fee that goes to banks

the National Retail Federation says the interchange fees cost households an average of $427 in 2008.

- amount varies depending on credit or debit
- amount varies depending on whether you sign your debit/ or punch in your debit card PIN

Retailers say they inevitably have to pass along costs. Is the convenience worth it? Would you pay differently if your bill was different based on how you paid? Do the agreements that prevent vendors from charging different cash/debit/credit prices distort consumer habits (rhetorical)?