Hard to say. I would pay well north of $1k since Ti frames (excepting the ghisallo) last a long time and you'll get lots of use from that bike. But OTOH there's not much of a market for those bikes anymore so it's hard to value them. The frame by itself is probably worth at least $500.
Personally, if it were in "like new" condition, with new tires, chain, etc. I could see myself paying closer to $2K for it. For a bike that was neglected $1K is more reasonable but I would rather pass in that case.