One of my friends who knows I'm in the market for a mac is doing the typical "don't buy mac because..." stuff. He said that with Mac, you have to pay for OS updates. Now, I'm not talking like OS 9 to X. But say from 10.5.5 to 10.5.6. Is this true? I tried googling it and didn't find much to back up his claim, so I'm leaning toward him being full of crap. Thanks.