How important is worldwide patents?

I am planning to start a company to develop, produce and sell a new product in the hiking category. The product does currently not exist in any form, and if patented and design protected I should have monopoly on the whole market (estimated to 1 million units sold at 100 USD a piece within 5 years after launch). When produced I will expect that the product is easy to copy by other companies, and I will therefore be appying for a patent as soon as the design is finalized in about a year. But how important is it to get the product patented worldwide? Should I get a patent in all major contries? EU/America/Canada etc? Where should I draw the line? Thanks for any inputs!