its worth what someone wants to pay for it.
thats a stupid answer but i've seen these go from $300-$3000+ in recent months so its really more about the market in your area, or if you're willing to ship it.
if it was me looking at it, and i was local, i'd give you $400 complete or so if everything other than the turbo checked out (its worth more as parts)...if i could hear it run, check compression, etc, or i was in a bind for a engine, i'd be willing to pay more.
the US never got these so you'll get the best money for it down there.