Majority of recent caveats show a price of around $750psf. Given the recent weak sentiments, I would suggest that you not pay above $750psf definitely, especially for a 'mid-floor' unit. Of cos, this suggestion ignores facing and condition of the unit(s)...
I would even suggest that perhaps you can delay your purchase a little if possible. True, prices may or may not fall, but they will definitely not increase in the short term. If you really cannot wait long, at least try to do your negotiations and purchase towards the end of the 'Ghost Month', when the market is traditionally quieter and sellers more open to negotiations. Anyway, that's just a couple of months away. If doing so might save you a few tens of thousands, why not just be that little bit more patient??