I would look at used also... for the simple reason...They dont build things like they used too! Older small engines are a dream to work on, have little to no plastic (new ones do)...Besides if you can pick up a decent 8hp for 600.00 and have it last 10 years... well I figure your ahead of the game..
If you want to consider used.. I would purchase it from a place that actually sells and services them new.. that way you know your getting something that has been looked at tuned and serviced by the professionals...
Here in Hamilton, Peters, O'Neils and Berts come to mind.
Gerritt.