A tiny dusty camera store I found on vacation had the drainpipe for about $400. I was $50 short… I'm not telling where it was in hopes of vacationing there next year and seeing it in the same window.
16-35. i had it and the 17-40 at the same time, and the shots i took didn't show a $1k difference in IQ between them. Kept the 17-40, returned the 16-35.
I bought an old version 1 400 f/2.8 but had problems with it (loose element inside) and it was never "sharp." Sold it for $2k on ebay but miss that nice huge glass.
Shot with a 500 f/4 IS at the 24 hours of daytona last year, had a blast using it, what a lens.. I will own one some day. Credit to the 300 2.8 IS I was also shooting with - it coupled with a 2x had just as sharp of photos as the bare 500.
And last but not least I'd really like to try the 200 f/2. Seems like one of Canon's best.
I've picked up the 17-55mm f/2.8 in a camera store too many times to count and never bought it. Don't know why I cave at the last minute. I've also done the same thing with the 50L, but was decisive and bought it just a few days ago. So, I can make my mind up, just not (yet) on the 17-55mm.
Good deals for used excellent Canon lenses are getting harder and harder to find recently. Only three years ago one reputable used camera gear online store had a few used L lenses on sale from time to time about 20% down from its original price in a good quality - now prices are all cranked up and used lenses are nearly as expensive as new lenses. At this time I found a used 45/2.8 T/S lens for about $800 - I hesitated since I just got my 24 T/S and wasn't sure if I would like T/S. Now you can't get one for this price! At least I manage to use my 24 T/S with teleconverter by loosing one stop if needed, but it works, too.
I don't think too many here would admit to stealing or "borrowing" a lens. However, some OF gave me his EOS 650 with EF 50 1.8 attached. Was a decent optic and the only lens I owned that I didn't actually purchase.