Forgive me for saying so, Larry...
but I think you're in a rut!
Why are you banging your head against a brick wall with "new home owners"?
"If you were in an area that housing sales were very slow, what would you offer a local business to incentivize them to be on your community website?"
I think that you need to step back, look around, and shed this "new home buyers" junk. The key word here IMHO, is "COMMUNITY". Increasing traffic and sales is the name of the game, and I'm betting that the businesses could care less about the status of the home owner!
Like I metioned, perhaps you just need to step back, look at the idea from another angle, and put a twist on it.