I own most models of TO and enjoy them all. If I had to keep only one, I guess it would be the 7G605. You can see them at:
http://antiqueradio.org/transoceanics.htm
You can download technical manuals from:
http://www.transoceanic.nostalgiaair.org/
If you're curious what your R7000-2 looks like inside, check out my article at:
http://antiqueradio.org/zenithr7000-2.htm
Note that the 1000 and 3000 models are fairly common, and you shouldn't have to bankrupt yourself to own one. I have owned two of each type and didn't spend more than $40 for any of them.
If you limit yourself to eBay, then of course you'll pay a premium. I bought one of my 3000-1s at a garage sale for $5.
Regards,
Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html