If you are serious about the seed thing: Don't buy from a store that has the seeds out in the area where they water the plants. Seeds need to be dry...very dry...in order to maintain germination.
I order much of my seed from Willhite's. I think it is whillhiteseeds.com, but go "ask." Their prices are very good! Much of the seed is open pollinated. Some of it is treated, and I don't believe that compromises the "organic" goal.
If you are "prepping" buy more seed that you will use in a year...generally that is even the smallest pack they sell, and store it in a cool dry place, or in the refrigerator.
If you are "seriously prepping" do this: Buy the seed, repackage it into small coin envelopes, label and date. Get the two quart canning jars, with the lids. With a punch, put a hole in the lid. Get a small cannister of nitrogen at a welding supply house. You'll need hoses and such. Pack a year's supply of seeds into one jar, or two. Have some duct tape cut, close by.
Nitrogen gas is harmless to you, but it drives out the air in a container. Put the nozzle of the hose into the little hole (after you have packed the jar and put the lid on!) and let the nitrogen go into the jar. Give it about a minute. Quickly take the nozzle out and apply the duct tape to the hole.
Date and label the jars.
You can use this same method with wheat, whole grain cereal, beans, etc. Buggy things cannot live without oxygen either, and the nitrogen does not hurt the food.