Well, this just crossed my path. I was browsing through 'Marktplaats.nl' and saw the 17-35/2.8 being offered locally. Also, I happened to have a friend interested in my 17-40/4 in case I ever wanted to get rid of it.
Normally 17-35's sell for €750-800, but this guy only had offers up to €500 when I emailed him. So he gladly accepted my offer of €650. When I went to pick the lens up the same evening, he told me that he got quite some higher offers after my email. But luckily he kept his word.
