Another perk of using a credit card is many of them have price protection. I do all my purchases on a Discover card, get 5% cash back (this quarter for hardware stores) and a 90 day price protection.
A word of warning - they also offer extended warranty, but it my experience it's worthless.
Bought a Bluray player on Discover, died after about a year. Filed a claim, Discover sends it to the insurance company they use to process claims. Fill out an 8 page form, send receipt, credit card statement, full warranty, invoice, etc. They come back and say they need an estimate. I tell them a repair estimate for the $100 item will cost $150. Discover says they don't need it, insurance company says they do. I tell them I will get it if they pay for it, they say no, I have to pay $150 to get coverage on a $100 item - so it will cost me $150 to get $100 back. We have been going back and forth for over a year now.
In comparison, Amex and Visa both sent checks in response to simply filing a claim online for extended warranties. Maybe the bigger concern is that we can't seem to make a reliable Bluray player
