Brexit shouldn't affect anything for overseas buyers for at least 2 years. Even then, the likelihood is that nothing will change for the USA.
We have done our best to maintain pricing over the last few years. We were due to have a small price increase shortly - but this is on hold for now.
We buy many parts overseas in $USD. Where we might make more profit on selling games in $USD, it costs us more money to build them. So it's a catch 22.
Those who have pre-ordered the game do not need to worry about the uncertainty of currencies, as their prices are locked in. If exchange rates go the other way, then we are the ones who will lose out.
We must keep U.S. and Canadian prices in $USD. North America shipping and support costs are incorporated into our margins.