Here are some of my favorite mail order seed places:

http://www.wildseedfarms.com/

http://www.americanmeadows.com/WildflowerSeeds.aspx

http://www.prairiemoon.com/

http://www.swallowtailgardenseeds.com/index.shtml

http://www.cheapseeds.com/

Also, here is a great link to a bunch of seed sites.

Here is a link that might be useful: Seed Sellers

Try this http://stores.ebay.com/grocoseeds
Very cheap and good seeds.
Larry

Clyde Robins

sunmark seeds, very hard to beat their prices.

http://www.sunmarkseeds.com

they just redesigned their website and its horrible. they have a "pacific NW mix" of wildflowers for $25 a pound. i haven't followed all the links above, but that price beats clyde robins and american meadows by a third.