From the US:
Silva Type 54 compass, £33 including shipping. Had to pay 17.5% Vat plus £5 handling. Still cheaper than UK price.
Second hand Bear recurve hunting bow. £45 incl shipping. Did not get charged vat.
Amateur radio transceiver kit. £55 incl shipping. Had to pay vat and handling. Still cheaper than UK.
Torch at £25 incl shipping - did not get charged VAT.
Various items under £18 (krill light, pocket knives) - none were charged VAT.
Books are VAT exempt - never been charged for these.
From Canada
Grohmann knife kit £31 inc shipping. Did not get charged VAT.
So....it is a bit of a lottery. Under £18 you should be ok. As you go over £18 you increase your chances of VAT and beyond £50 I think it is likely. So far I have never paid duty - just VAT and handling. I think that theycan charge duty on the item AND the shipping, and the slap VAT on top - so you pay tax on the tax!!!!
Having said that, in every case I would still have saved by buying abroad even if I had to pay VAT. And in 53 ebay trades I have never had a bad deal or an item lost.