Here's the latest answer
we've reverted back to allowing one hour for edits on the original title and post. This was done to prevent people from removing all the content from "for sale" posts. We felt that original post and price were an important part of the thread for historic purposes, ie, someone wants to know what item X typically gets posted for.
While we realize some people update their thread with "new pics posted", etc, we thought that was rare enough that those people could just post on the end of their thread to bring it back to the top.
We'll look around and see if we can restrict that to the buy/sell forums only..