Seed Savers is a local nursery (15 minute drive from our home) and offers heritage seeds that can be harvested and regrown the following year from your own garden. Simple vegetable seed packets start at 2.50$ a packet.
In the past I have also purchased from Gurneys. This is a great source for those who are interested in good quality seeds and are serious about gardening. Especially for those who would like to grow your own groceries in your back yard.
Of course there are many other nurseries and seed companies a person can choose from. If possible check out your local nursery and see what they offer. You might find some good deals for the season.