I've ordered vinyl from US Amazon sellers (via the UK Amazon site) for years and years, cos most of the time they're cheaper. However I've been hit three times over the last six months with Customs Charges which apparently they can make you pay on.. err, pretty much anything?

The frustrating thing is, the charge is only about three quid, but there is an £8 handling fee which makes it excruciatingly expensive. Is the seller in any way liable for these charges? Is there any way to pay them in advance so I don't get hit by the handling fees? And why am I getting loads of these customs fees now, after doing this for years, is it bad luck or are they "cracking down" or something?