Well, in light of the surprising results of the referendum on Thursday, it is unsurprising to find that the Pound to USD exchange rate has collapsed. ($1.37 to the £ as of this writing [and a similar collapse against the Euro])
Here are some great British companies you should patronize in a show of solidarity (and to get some great deals on great figures)
Perry Miniatures Home of the fabulous Perry Brothers.
GZG Astounding 15mm scifi, as well as 6mm and space ships
Pendraken Miniatures 10mm
Hasslefree miniatures fantastic 28mm figures
Brigade Models 6mm/space/15mm
I know that there are ton of smaller companies out there, so let me know in comments where you plan to shop.