Something else to read carefully is the statement of warranty. On the really low priced Dells, if you look carefully, you'll see a 1 year tech support warranty (for telephone support only), and you get a 90 day warranty on the hardware. You can upgrade the warranty, but it will cost extra. This is only on the Dimension line.
Mark
That's new. Anyway, "upgrading" to a one year warranty is $17, which probably won't break the bank for people concerned about such things.