Sex Sells was just the working title and at the time Jon didn't know weather to make another solo album or a band album. There was a song called Sex Sells plus a bunch of other demo's that never made the light of day. We got to hear some of them at the 10th anniversary fan club bash in New Jersey and were asked by Jon to vote on which ones we liked best. A rich man living in a poor mans house was one and also Just Older. But Just Older was called "Older" to begin with and was slightly different to the version that made it onto Crush.
I guess in the end Jon decided to go with another band album. If anyone was around in 2000 they would have been able to see the making of Crush every day from the studio as it was streaming on Bon Jovi.com.

Hope this helps!!