That $1.50, by the way, is per shipped package. It could consist of 6 items .. and only 1 charge.
They do have some items that are odd-shaped and/or breakable, but even with the worst combination they've had to cope with - it has never exceeded $2.50.
Shurtuff bags, bubble wrap, etc are all new - the only 're-use' product is cardboard - but collecting that is my job. Clean material from a local supermarket - and absolutely no chicken nugget boxes!
From my estimate, they only (barely) cover material costs - nothing for their time.