By the time you take that thing apart, and reassemble it, you'll be out 3-4 hours of your day, and, you'll be lucky if it doesn't leak once you are done. Better order a new set of gaskets now before you perform you first disassembly. Ask any brewery about plate chiller cleaning.
Also, breweries rarely disassemble their plate chillers, maybe once a year, and that is if they are on nearly constant brewing cycles. They do however like that they can use caustic and acid to clean them without affecting the "joining metal" of brazed chillers. Also noticed that Sabco says that the gaskets are glued. If you disassemble, order some glue too.
For a homebrewer, $700 is WAY out of line, but I am really impressed that it only cost that much.
On the flip side, I recently installed a B2-23a 30 plate in my rig from Dudadiesel. It works better than my old 40 plate B3-12a. I bake it for 1 hour at 275 in my oven prior to use, and I use a hop screen. After use I clean it with 60psi water (tap) and then oxyclean. It works great, and is a lot smaller than the above mentioned chiller.