Think I saw this about 6 months ago.
http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=310240021830#ht_1709wt_1021
32,900 Euro=43,500 USD. And as far as I can tell, no keyboard or ribbon controllers.
Who’s bidding first? 
You might have seen the 55a that keeps being relisted at lower micro-cent BIN
This one is not just a IIIc, but IIIc with dual sequencer expansion option. Quite rare and worth the price.
Agreed.
But IMO it’s only worth the price that a buyer is willing to pay for it. As I mentioned before, I think this was up on the 'bay before some months ago. A potential buyer might have flaked out, or it simply didn’t generate any bids–who knows? The individual module photos seem to show them having had lots of use. It’s very possible that a major restoration would be in order, adding anywhere from 20%-50% (my guess) to the asking price. Then there’s the keyboard and ribbon controllers to consider. Good luck to the seller, though.