Without credit cards you are missing out on a lot of money. I pay them off every month and they give from 1 to 5 % back depneding on what card I use and what I buy.
Most even gave me from $ 100 to $ 200 back just to get the card and charge $ 1000 or so in 2 or 3 months. Grocery bill takes care of that.
About 2 years ago I bought a new car on a 7 year credit plan. I could have taken it out of my IRA with no problem, but would have had to pay tax on some of it. Plus as long as it stays in the IRA it is making intrist, so that probably saves me another $ 5000 over the 7 years.
It is good to take advantage of other peoples money.