http://www.pc.gc.ca/eng/pn-np/bc/pac...v/activ6a.aspx

That link will have all the information you need to plan your trip. We went outside of permit season (meaning we didn't have to make a reservation, still had to get a permit) and that worked well for us. I spent around $500 total: ferries to/from Washington, gas from Oregon to Washington, hotel in Port Renfrew one night, permits, meals off trail, meals on trail, trail bus, etc.

I want to go again...it's amazing.