Does anyone have an idea how much to replace a canvas top for a 1998 8foot pop up? Or do you know a company that does it?

A Google search turns up several possibilities:

https://www.google.com/search?q=replacement+pop+up+canvas+tops&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=fflb