I got my i-gucci from jomashop.com for around 800$
That's the best you're going to find, at Sak's / Niemans they're 1300$ + tax.
With Gucci (Also other luxe brands) watches, you won't find them "on sale." - unless they are very old models at bargain websites (overstock, etc.).
They also need to be sold through authorised resellers in order to get a certificate of authenticity / warranty card. Jomashop = not authorized reseller, which is why they sell it for 800 instead of 1300. Be careful from buying from sites like that though...some of them will not provide warrantys at all -- and if your expensive item breaks, you're screwed. Jomashop provides a 2 year warranty though, which is the same that you'd get from Gucci if you bought it from Niemans.