Here is the response:
"Garmin Australasia does not change its pricing to match foreign currency exchange rates.
General business factors drive our pricing as they do for any business in Australia for example, market size, labor rates, logistics and warehousing and IT infrastructure etc.
Comparing AU pricing with Europe or America is simply not the same thing as the markets are extremely different in size and consumer trends."

The markup was 50% on the US price for a digital download presumably from the US (for shipping, wharehousing, IT, dealer markup?). Additionally Garmin restricts Australians from making this purchase in the US. Garmin US advertise the Montana 650t for 629US (601 AUS) and it can be purchased in Australia for $655 AUS (No Frills store). A markup of 9% for shipping etc. sounds reasonable given dealers will purchase it for less than 601US.

Fringe. Yes, Aussie stores will come undone if they do not move with the market. A mate just told me of a friend in Europe who is Elancing out his employed work for a third of his wage and running a business from his workplace in the meantime. That one is a bit dodgy but that is the sort of creative thinking needed.

Schermann. Thanks for that. I knew it could be done but was not sure how.