In reply to all:
As everyone is agreed that cameras2u are pretty reliable, I shall pose another question.
While looking for a bargain for this lens I have inevitably been watching fleabay, like a hungry hawk. I have watched many and even bid on a few 10-20's.
After mistakenly adding a few f-mounts to my watch list I noticed that there is a difference in what nikon users and canon users pay for their used gear, with nikon users paying more, sometimes a lot more.
The sigma 10-20 for canon users mainly went for £205-£230, the most spent was £231. The same lens for nikon users goes for £220-£260, the highest bid I have seen was £267. The two highest prices went within minutes of each other and were almost identical in terms of description, both 'mint' as new with the canon actually being newer with 6 months left on the warranty.
So why do nikon users pay more for their used gear?