My guess is you are probably looking at US$1 - US$1.50 per mile for that size boat. Check out uShip and you can find quotes for similar size boats for cross country trips. Should be able to get it in the lower end of that range if you are flexible with timing so the shipper can arrange a haul back to spread out their costs. That also assumes the boat comes a roadworthy trailer that the shipper is happy to haul. If it were me, I would have a spare wheel/bearing assembly attached on the trailer and ready to go.
If you are using the shipper's trailer, you'll probably be in the top end of that range but you won't have to go through the process of importing the trailer (which isn't really a big deal, but adds another step to getting your boat here).
You may want to pick the boat up in Blaine/Bellingham . I recently had a boat hauled from South Carolina and the shippers wanted double the rate for any mileage in Canada as they had to subcontract to a Canadian driver insured for that leg of the journey. I had my boat dropped off in Blaine last Thursday and brought it up on the water on Friday (coldest day in the last four years!).
You won't pay any taxes on the shipping part, just sales tax (both GST
and PST) on the purchase price when bringing the boat into Canada. If you bring the boat in by water, you can do this over the phone from the designated CBSA dock at your first port of call. Took me 10 minutes.
Check out
www.thehulltruth.com if you haven't already for recommendations on shippers (and the buy and sell section as well - there is a 2006 GW Gulfstream in SC that has been for sale since September). That's where I found my boat and the shipper I ended up using (Flynn Marine) which I was very happy with and would recommend.