godzilla,
the duron 700's you are seeing on pricewatch for 59.00 are the oem version, which only has a warranty of usually 90 days to 1 year. sometimes the warranty on these oem's are store warranties as well.
the ones listed on this deal are the retail boxed duron 700's which come w/ a 3 year AMD warranty and they have factory heatsink and fans included.
they really are awesome about the warranty too. my friend said he fried his amdk6-2 300 accidentally and they sent him a new one without any questions.... the only thing was, when he got his package, it was actually an amdk62-500!!!!! they were out of the 300's so gave him a free upgrade LOL talk about a deal :Q
otherwise however, they are exactly identical in every way. imho, its very much worth it to spend the extra $15-20 dollars to get the retail version just for the warranty. especially if you are thinking of overclocking it.