postage-pinchpenny
Someone who constantly attempts to minimize the cost of sending his outgoing mail, perhaps even resorting to dishonest/advantage-taking measures to save even more.
One of the most effective ways to be a postage-pinchpenny is to simply "reverse the charges" --- i.e., write your mail-piece's recipient's name and address in the space where its sender's address-information is supposed to go (and vice-versa), then slap a few cents'-worth of postage on the envelope/box so that it still won't cost you much to ship your parcel but it won't blatantly look as if you are merely trying to mail the parcel for free, and deposit your item in the Post Office's "anonymous" mail-slot or "outside box" to avoid your having to face the scrutinizing eyes of a postal employee who naturally would just reject the package right off. Then, of course, the Post Office will have no choice but to just unwittingly go ahead and deliver your package to its intended recipient (incorrectly believing that he is the sender who grossly under-stamped the package, and that they are therefore merely performing a "returned to sender for postage" procedure); this works best for merely "local-destination" mail, since the Post Office might balk --- and be suspicious about how this "distantly"-return-addressed parcel ever got into their "local" outgoing-mail box --- at expensively "returning" a mail-piece to a faraway location.