I think the Hawk is a honda model that is US-based. The UK equivalent was the NT range (the honda "bros"). There's a few "bros" around but I haven't seen nor heard of any Hawks in Australia. It would be rare, especially if it's running, but I think due to the level of rarity there would also not be much demand. In terms of value I'd suggest an engine is worth what someone will pay for it, for one like this I don't think you'd be getting much. Just my 2c though, others may have different experiences.
It is complete, and will turn over, this engine has never been taken apart. Thanks I was just wanting a price to start with, and to see if this engine is rare.
What value is it to you, and how bad do you need it? My suggestion would be to start at $100, you can always go up from there. I base that on buying a 400cc Bros for $350 two years ago, but had to spend nearly a $1,000 on it by the time it was registered.