I have no idea but I recall years ago many local establishments would offer their remaining seed packets on sale at the end of the season. Not done around my part of the country anymore so I have to wonder if all the local stores are selling their seed packets on consignment?

If you do find a bargain, always look at the back of the seed packet as they will stamp on the "Packed for 2019". Or you will see a germination test on the back too. Their is now law against selling seeds from the previous season as long as the germination tests show the seed is still viable enough. I recall a seed company in my state mentioning this as they would test all leftover seed and determine if viable enough to offer for sale the following year or not.

I am simply amazed by the ignorance of many gardeners. I constantly run into friends and family members who ask me to pick up some seeds for them. When i ask what they did with those from last year, they tell me they "threw out any extra" after planting the garden. So silly. Many seeds will keep viable more than one year. Bean and squash seeds will easily keep 3-4 years if stored properly. Peppers and onions are an exception, those I buy every year. Cucumbers? I keep cuke seeds for 3 years too.