I wouldn't pay any money at the moment. I have little money to spare. I do know of a few collectors this would be very useful to, but to not damage a card would be highly difficult to achieve. The edges of the cards are very susceptible to damage.
I have a few hundred Pokemon cards and thousands of Yu-Gi-Oh ones. I wouldn't pay for any device to sort my cards out though to be honest. I only take a small percentage of YGO cards with me in trade binders to tournaments and the rest just sit in tins which I occasionally scavenge through for useful commons. I wouldn't use the device very often at all that's the issue.
One issue I thought of with this is that this would make it easy to steal my entire collection, if it were an easy to store device. I'd rather have a device that only did the sorting, and the storing would be done by me, since sorting is the real tedious portion for me and storing is much, much easier. If it had highly flexible options for sorting, it would be a near-definite buy for me.
I guess by color, but that is the easiest sorting method for me. If it were possible, I would like to be able to sort by sets or rarity, but the former would probably require updating the software or firmware for every set, and holofoil rares would be difficult to sort from other holofoil cards.