This effect is no longer available as a new trick, you will have to pick one up on Ebay or at a used magic auction, but they are not rare and you should be able to acquire one. This would have to be the number one issue with this effect, it is not something that you can just purchase off the shelf.
Couple issues, the effect cannot be done surrounded, it has slight angle issues and you are limited in size as far as what you can use in the boxes. The effect requires practice to work smoothly. The effect is not examinable.
The good qualities are that the effect is relatively quiet, unless you drop something it does not talk. The effect is easy and the props are of good quality. You can use other items besides a skull and pumpkin (I believe the instructions talk about an exchange of a lady's watch for a man's watch). The effect is a very good miniature version of a stage illusion which is somewhat rare, most times when an illusion is downsized to parlor it does not go off as well. You can add more ribbons to secure the box (in the demo I only added one so as to save time, but most do two ribbons, having them cross across the box like you would wrap a present). There are no duplicates, only one skeleton and one pumpkin are used and they could be marked if needed.
The transposition seems to really go over well especially with kids. Although the boxes cannot be handed out, the pumpkin and skeleton are actually small candy holders and can be given out to the kids after the performance. If for some reason they don't make it back to you its not a big deal, they are available at Walmart in packages of nine for about 2 bucks or so.