Not really for the used stuff since i got a solid 1000+ feedback ebay account and sellera agree to ship most of the times when they see that.
For the lens rentals, thats a whole different story tho. Theres close to nothing.
I was ready to buy a 300mm 2.8G last week. It was at 3k instead of 6; brand new. It didnt stay long on the market but oh well. I would like to get something longer; 400 would be ideal; and I could settle for something slower then 2.8; like 4; but dont want to get a lens too old either. Choices are limited and good deals on quality used lenses even rarer.
I'm not in a rush; but am keeping an eye open for deals.