Actually (I'm going to get flamed here), the price isn't all that bad.

Now saying $9,200 for a snow blower is a lot is true but even 5K for a rear mount is a lot.
If it was all about $$ we could just buy a bunch of walk behinds (3 33" ones maybe) and mount them on the loader for much cheaper. (No worried about HP)
I'm trading in my 3720 for a 4720 - It's currently speced with a rear 84" blower but I'm thinking about this - Saw it at the dealer and it looks pretty cool. Much more ruggedly built than I would have thought. Also, the 'ears' on the back of the power pack lead me to believe (if you could deal with the length) you might be able to put a small blade back there if the dimensions match 3pt (I think they do). I'd worry a little about bending the cage of the power pack but it's pretty heavy. I'm sure this would void your warranty though.
I'm not sure where you get a blower the 1/3 of the price, but a front mount on a 3720 (I have one probably is around 6K+ right now (was about 5K when I got it between the blower, drive shaft, front 3pt hitch, etc., etc., etc. And it's not terrible to take off, but difficult enough once I take the loader off and put it on I'm not swapping back. And my 3720 blower is only 59". Come to think of it, my 47" blower on my 2305 is probably about 3500+ now (It was about 3K in 2005 between the blower, drive shaft, front PTO kit, front lift kit, etc., etc.
They also do make rear PTO front blowers (a whole assembly/shaft goes UNDER the tractor) but those are almost 9K also and where do you store such a long rig with all the mechanicals in the off season? (My issue with them). (You drive over them, hook up the PTO, etc, then put on the blower). You also lose a lot of ground clearance (You lose some with the JD front blower mounts on the 2000/3000 series also.
At least with the rear blower you buy the blower you are done. With the exception of
options (remote chute, etc.) you don't need to double the price with crap you need to mount it. So my point is that it's not a fair comparison front blower to rear blower.
Frontier (same brand comparison) rear blowers are in the 5000-6000+ range and those are simple compared to either a mechanical front mount, or a hydraulic.
Also, what this basically is is a skid steer blower with JD mounts and a rear power pack. SS blowers go from around 6-7K (Very low end) to 12K+ and that's without the power pack.
Now, for an Idea: (I'm too old and lazy but maybe somebody can make one and I can copy it).
I have an extra Harbor Freight quick hitch I bought and some JD mount hooks and pins I've been meaning to weld together so I have a standard 3pt hitch on the loader - Great for raking, moving implements, etc. Now, if I took that further and either had a mechanical linkage/reducer to the front PTO. The other option would be a PTO pump (rear or front) with lines running to a shaft on the welded up unit. So basically ANY PTO powered 540 rig would be mountable on the loader (using a drive shaft just like the rear). I'd love to mount a small bushhog this way (maybe a 4'). Anyway, I'm still dreaming.
One other thing also if you are trying to justify it. Once you have the rear power pack, if you get a skid steer mount you are open to all sorts of nice hydraulic accessories for skid steers (used also) that the tractor hydraulics wouldn't run - Hydraulic brushes, etc.
