I don't disagree as they are providing fans with a service they otherwise would not have access to. But they would make a profit on every sheet they sell & for it to be a viable business they would need to make at least 100% mark up to even bother with it otherwise they would lose money on every transaction.
The most expensive label sheets would be the metallic G1 replica ones & even of they bought from a company like Staples at retail the quantity they consume would mean their actual cost pre production would be minimal & more than likely they buy them under a contract price arrangement. Add in the cost of printing & it still won't add up to a fraction of what they sell them for in the marketplace.
I don't know how they "cut" the labels but i would assume it would be using a die & that would be the most expensive part if they do it that way.