Apple's online store is currently offering a variety of Mac models starting as low as $849. Two Mac models are priced at $849, the 20-inch 2.4GHz iMac and 2.0GHz white MacBook. MacBook Airs are available for as low as $999 for the 1.6GHz model with 2GB of memory and 80GB hard drive. The 24-inch, 2.66GHz iMac with 4GB of memory and 640GB hard drive is available for $1299. Unibody MacBook models