I think that this is the best of all worlds - expense and ensuring seeds aren't "butter".One of the dollar stores sells padded/bubble envelopes in packages of 4 or 5. I normally keep a stock of these on hand. Postage is usually $0.85 - $1.20 range. I've never figured out why they sometimes charge more when the weight is about the same. They don't always put it through the gauge to measure the thickness. Usually when they measure it and it is under they charge the lower rate. Go figure.