I think the resounding answer is......buy your "small" seeds from one of the better seed houses said above......and buy Rye, Oats, Wheat, corn and beans, and other large volume seeds from a local source to reduce shipping costs. Lots of good local sources for seeds.....if you do a little shopping. I have learned to ignore a dollar or two per bag when I find the right source.
Ten bags at an extra dollar or two / bag is a small price to pay for the right stuff. Everyone needs to make a buck.