I got my Widebody cab for $160 and had to drive 2 hours to pick it up! Still a great deal though since it had its original monitor in it still. I had to replace all of the artwork and find lots of replacement parts. The toughest part of restoring a widebody is that its really hard to get just the right things for it. The standard Nintendo cab is much easier to work with, plus if you wanted to make it into some other Nintendo game then its relatively easy to convert it over.
Also, its important to know that the control panel artwork is much different for a widebody Mario Bros than it is for the conversion.
In my experience in Upstate New York I couldn't find even an empty standard nintendo cab for less than $100. I got really lucky with my widebody. The guy didn't know what he had.