The Rand is a unit of currency used in the Magic Kingdom. It is not a physical coin or treasure, but a barter credit. Casters in the Magic Kingdom can offer their services or created scrolls to other casters in exchange for Shmuckers, but more often it is done for Rands.
Does not appear to be used outside the Magic Kingdom. Possible reference to Ayn Rand. May also be a reference to the real-world currency of the same name. Could also be tied into a Janice Rand (from Star Trek) reference, since the first use of the currency was when Sizemore paid Janis for hippiemancy lessons. May also be a reference to the leading character of Robert Jordan's "Wheel of Time" series, Randal'Thor.
Rands may be used as a way to limit the power of Moneymancers in the Magic Kingdom by existing outside their sphere of influence, but this will not be able to be confirmed until more is known about them.