Probably a 50/1.7. That's worth a bit over $100 AUD (say 140?) depending on condition. Maxxum 7000 worth maybe 20 if working well (and you're interested in film). The sigma lens - well depends, it might be worth getting, but if you plan to upgrade to an a700 or similar in the future, the faster AF drives tend to strip the gears in those lenses.
I'd say 200 is a little high, but if it's the 50/1.4, it's a good deal.