There is a company called watersun together that sells almost all it's seeds for 99cents, most expensive is i think 1.19 i ordered a bunch online and to my surprise, when they came, they were all Burpee seeds. i recd them the same week i ordered. and have gone back twice for more. i dont know what you are looking for but they have a decent selection if you dont want uncommon seeds.
i found a site called CheapSeeds. huge amount of seeds for a very resonable price and the shipping is free. you also get great personalized service. bought some to try it out, went back and bought lots more. the first bunch i bought are already spouting.