I called a local manufacturer in Bloomington IL, and they kind of stick to a template (off the lot) for the lawnboys, said it'd be between $1k and $2k depending on # of axles and brakes etc.
The used one I'm after will be about $500.
In your climate, I think the lawn boys have a more perenial market, but they are in the paper Jack. My neighbor used an wrecked RV trailer (try scrap yards near where landfalling hurricanes have been,) ripped the living piece off and just used wooden boards, was less than $200, the lumber was the most expensive part.