Trade.io now takes the top spot. Sold in 2010 on Sedo for $4,000 it went for $88,000 on Park.io Monday.
The domain name has been developed, there is a note,
Even though the trade.io exchange is in hibernation, the Liquidity Pool is alive and well and has evolved into the TIOprime Pool.
Battery.io also sold for $24,000 keeping the .io train moving. Polly.io sold for $28,888 a week ago.