Alexander, First, let me congratulate you on considering the purchase. I also must say Bryan Oetting is as capable as they come and would be a great pilot to fly your new plane to you in Seattle...regardless of where the plane is located once you find the one to buy.
As for the cost, A couple of years ago, I delivered a 150/150 from Houston, Texas to Grants Pass, Oregon so an old Grandpa-to-be could have a nice plane.

That trip, flown over 4 days with three nights in a hotel ended up costing right at 1000 dollars. Like Bryan, my delivery fee was nothing. I did it for the experience. My schedule wouldn't allow me to do it this year, but Bryan has his Commercial Pilot's license, Instrument rating, and he's president of his local Good-ole-boy club. He's also owned a 150 and currently owns a Cherokee 180. He gave it a girl's name, but don't hold that against him.

I've always thought Seattle would be pretty for a visit, but I hear it's gray and cloudy most of the time. Good luck with your airplane purchase. Bart's is a nice one.