Not sure where in Washington State you are, but there is a spring shop in Everett, Wa that does good work. as you said this is the most expensive route to go. I took my 87 Toyota 1 ton flatbed dually in there for a quote. They wanted something like $600 to re-arch my springs and add 2 new ones on each side. I did not get the work done, but I know they do good work there. Here is the link
http://www.aalbubrothers.com/index.html