Seedfork said:...
I went to Tractor Supply yesterday and priced some Burpee radish seed, wow over three dollars a pack. Headed to the farmers co-op and that is when I realized that buying by the oz. was really the way to go. At first I saw the $6.00 price 
...that was for a pound! 
Yup! Pay a lot for one tiny pinch ... or a pay a little more for a lifetime supply.
I agree that you can get
much longer shelf life out of seeds sealed up and kept cool or cold, over a shed with varying heat and humidity - including high heat and humidity!
Three years is a realistic goal and should be easy to accomplish without jumping through a bunch of fussy hoops. Maybe ZIPlocing them into annual batches, would protect Year Two and Year Three seeds from condensation each time you dig into the Year One seeds.
Or my concern about condensation may be exaggerated.
Silica gel is only a few dollars per pound at craft store flower-drying isles.
Seed swaps let you trade one ounce of one seed type for small packets of ten different seed types, if you can find what you want.
