800 is about the going rate for the low end ones. I buy them used people trade them in when they realize a thousand dollar gun does not make you a good shot. i paid 600 for my edc w/ night sights mag well 3 of the cheapest 1911 mags i have ever felt and a 9 dollar uncle mikes holster.
I would lean towards the Sig. The external extractor is heresy contradictory to John Moses Brownings blue-prints, but all my buddies that have Kimbers have had FTF/FTE issues - especially during the break-in period. Not sure if Sigs are better...but...
Take this with a grain of salt since I do not or probably will not own a 1911. I like 'em but they're too much $$$ for what they are.