What are the pro's and con's of buying a camera from the US where they are significantly cheaper?

Here's one i found earlier: Canon XF100 HD Professional Camcorder on eBay (end time 02-Apr-11 00:24:08 BST) (http://cgi.ebay.co.uk/Canon-XF100-HD-Professional-Camcorder-/130493154928?pt=Camcorders_Professional_Video_Cameras&hash=item1e61ff8670#ht_9372wt_927)

Three big objections to buying from this eBay listing would be that it's NTSC rather than PAL, the difficulty of getting anything fixed under warranty & the fact that you will have to VAT & customs duty plus shippers fees totalling at least 25% on top of that headline price. Any one of these issues would be enough to deter me from purchasing.

Yes, agreed. Warranty and support are serious considerations as with most complex electronics, things can and do go wrong and a couple of hundred pounds saved now are as nothing compared to the catastrophic damage that can be done to your business/reputation if your gear lets you down when you're busy and there's no support for it.

In the case of the XF cameras, this is a particularly bad idea, of course, because this is not a world camera like some of the Sony and Pana models: The model sold in the U.S. does not record in PAL-compatible frame rates (i.e. 50i and 25P). You'd have to pay several hundred pounds to Canon UK or USA to get them to enable all frame rates. If you wait until it gets to the UK, you might find that Canon UK won't do it on a model you've imported yourself!

As i thought re HMSC. Completely forgot about the PAL/NTSC issue since i thought these cam's did both. And then there's the warranty.
I'm actually moving to Bangkok, so it would be interesting to see what the prices are like there. Apple computers are around 20% cheaper in Thailand and i'm looking for a new MBP, but haven't been able to track down prices for the XF there.

Thanks for your input.

PS, am i right in thinking tax is not applicable to used equipment?

You'll get hit with an import duty (based on declared value) for anything you ship in, used or not. Within the UK, businesses have to charge VAT even on used gear (if they're VAT-registered). Private individuals don't have to charge VAT, of course.