Is there a rule of thumb, or basic ballpark figure, for what it takes to make an old junker home disappear?
You need to provide more information. Size, condition, location etc. Cost to do it yourself will be different than hiring a contractor. Contractor cost varies from area to area and you need to know if you are recovering the value of any metal. Are you having it towed away or dismantled on site.
Many may suggest what they paid but that may not be anywhere near what you may pay.
In the midwest, where most of our parks are, we pay around $1,000 to get an old junker (single wide) hauled-off to the dump. That’s about $500 in dump fees, and about $500 in revenue for the mover.
That said, we have had a few home burn(!), and when they are in that condition they are not road-worthy; they then must be torn-down in place and hauled-off in a 30-yard dumpster. Such tear-downs generally cost us $2,000.
Of course, you could try any/all of this demolition yourself, but hopefully you are busy enough buying parks that such activity would not be a good use of your time.
To your continued success,