A year or so ago, someone in the other Canon forum said he bought a the MK1 version with IS for $9xx. (local craigslist) And later on got a call from a cop ask him to send that lens to the police station as an evidience since it was a stolen item. (Someone broken into a studio and cleared it out)
So if you are able to find the MKII for $1000, chances are .... either it is broken or hot.