Magic: the Gathering in the UK
Basically, if you're importing goods that would be VATable under UK law, then you may be liable for VAT on those purchases.
Normally VAT is collected by the seller when you buy something, and just added in to the sales price. But when you're buying from outside the EU, you have to charge yourself VAT instead.
For small items / gifts, this is usually not enforced as the cost of doing so exceeds the potential revenue.
The only way to get your VAT back on something you've purchased is to register as a supplier of VATable supplies, charge VAT on your sales, and reclaim your input VAT on your VAT return.
I would have done, but Mike was a bit too savvy to pre-order Vengevines at £10/each!