It isn't clear if you need the existing $99.99 2x3 inch plate transmission hologram kit for the upgrade. If so, that is a bit weird, as the upgrade kit comes with a new laser, new laser mount, new spacer, and new plateholder - isn't that pretty much everything from the 2x3 inch kit?
It is a bit clearer that you need to have the existing reflection hologram upgrade kit if you expect to use the 4x5 inch upgrade for reflection holograms. The 4x5 inch refill kit is about $13 per plate, a big step up from the 2x3 inch refill kit which is $4 per plate.
Anyway, this is a pretty cool development. I wonder if it is as easy to make 4x5 inch holograms using the litiholo film as it is to make the 2x3 ones. That is more area of the plate to vibrate during the exposure. I'm putting this one on the wish list, but my first goal is to