Since international shipping is $10.50, putting the cost per shirt at $23.50, but shipping for additional shirts is only $1, if there was enough interest I'd be happy to front a UK HNLondon Meetup group-buy, with all costs shared equally, and shirts to be distributed at the next event following their delivery.
We used to use a cheaper international shipping service, but things would get lost too often and we hated seeing people wait weeks for their tees. We recently upgraded to USPS Priority International.
Shipping simple tshirts piecemeal seems so terribly wasteful to me.
We'll continue to look into it though, perhaps when we reach a certain scale we'll be able to command better prices.
So take this into account if taking orders or money from people, you might end up with a 20% VAT bill when they get delivered that purchasers may decide they don't want to pay.
Email: iwantone@hntee.33m.co with color and size if you're in.