The last one I saw for sale was just the motherboard and I got outbid, despite bidding a few hundred bucks.. so I hope your wallet is deep 'cos you'll be bidding against me for starters.
They
do come up, but rarely are they fully working as the design and software was never finalised that I know of, so even when one does come up it's likely to have faulty hardware or ROM....
It's a similar situation to the Ti99/8 which occasionally come up but are as often as not faulty non-fully-working prototypes.
