Jim Key is selling his 31" Nautilus, fully built, assembled, painted and weathered.
The asking price is $900US plus shipping. I'm guessing you could get it almost anywhere in the US for about $30 or $40. It will require extra care in packing, as its pre-assembled and not in kit form.
If you're interested, please email me at firstname.lastname@example.org
and we'll get you hooked up.