My Glock 17 has 9,500 rounds on it, runs great. 10,000 not really a lot as far as the service life of the weapon - now compared to a lot of other pistols it might be a lot because lots of folks just don't shoot their guns much.
If you are really set on a Sig and you don;t have much choice because of your location, I'd say go for it. A little hard for a bunch of Americans to give you advice, we're not in your market. If you buy it I would just swap in new springs and so forth, just keep an eye on things during routine maintenance. Also I would call Sig and ask them - if the frame cracks what would their policy be on replacing the frame and would that be a pain in NZ?
ETA: I saw you are buying a G17. Good choice and as others have said, better value especially at the prices you mentioned.