That's what the going rate for the British GP has been for some time, £209 for a three day pass (with a grandstand seat) this year. At least in Montreal you're almost guaranteed good weather.
Doesn't matter if that's CAD or USD (the rates are pretty much the same at 1.966 and 1.98 respectively) $395 is about £1 either side of £200. No dearer than going to Silvo for the weekend. If the tickets, flights and hotel were all in budget I know where I'd rather be