it depends but

It depends on the model, and on whether or not it is still within the Apple care period if you want to buy it.

My cheapest was $499 for a midrange macbook and my most recent was $650 for a 20 inch screen iMac.

I know people who have often had good luck on craigslist esp lately with some people in fire sale mentality they have been giving them away for some cash.

At the time I bought mine my sister and mom both bought PCs for $400 and real cheapie for my Mom for $300 more like a netbook. They have already crashed a few times each plus have been stuck with Vista and problems with apps.

If a person has more time and patience than money, then I understand going the PC route but you will pay with time and inconvenience. For one or two hundred more think of all the time and inconvenience saved. A decent mac is more like an investment in my view.