Tru Peach, I get jars at goodwill and thrift stores. You can pick up a box of quart size for like $3. I also use them to pack our honey in, because honey does not require processing.
Sometimes I am really lucky and get the really old fashioned ones with the glass lid. Finding the gasket for these kind is harder, we have to order on line. I use the old fasioned ones mostly for honey. Also because I do can, I seem to have an abundance of jars.
I never shipped them but you are right that would make it expensive, not only for the weight but the bubble wrap to package them in. So for your ship to recipients your cellophane bag idea is great.