Here's the catch. You won't be able to find it in any stores outside Japan. However I asked the sales rep if he would ship overseas and apparently he does.
I'd rate it on par to the CLAS/HP-P1 only in it's upgraded form :-
Here's what I wrote for someone else on PM :-
Base versions Y34,800 (regardless of amp chosen below)
1) Go-DAP 4.0 Muses 8820 amp
2) Go-DAP 4.0 BurrBrown (OPA2134) amp (Between the two, I prefer BurrBrown)
If you're going only for the base models above, I have a preference to the BurrBrown over Muses. It had slightly better lower and upper extensions.
Now for the upgrades
a) amp only +Y9,800 (regardless of amp chosen below). Above amp versions will be redundant and replaced by one of the chosen below.
i) OP-275 (nice, smoother than the BurrBrown above)
ii) AD8397 (my fav, seems slightly nicer treble extension over the OP-275)
iii) OPA-2604 (never experienced)
b) DAC improvement (Muse F95). It's still the same DAC but they change (or add) the capacitor to make it smoother (+ Y6,800)
c) gain improvement (RK73). The RK73 resistor is supposed to change the gain to allow smoother (controlled?) current flow through the DAC. Y+ Y4,800)
d) Package Upgrade #1: choice of amp above + DAC improvement (+ Y14,800)
e) Package Upgrade #2: choice of amp above + gain improvement (+ Y12,800)
f) Package Upgrade #3: amp + DAC + gain upgrade (+ Y17,800)
So for example for my two Go-DAPs (or one I kept and another I sold to my friend), I went for full package #3 upgrade for both. Each costing Y34,800 + Y17,800 = Y52,600. Plus delivery on top of that.
Notes about my Go-DAPs :-
* Pre-upgrade, they sounded good but somewhat grainy. I still preferred my HP-P1+Pico Slim, or CLAS+Pico Slim combo. Naturally both these were bulkier than the Go-DAP.
* After upgrading both (1xGo-DAP was the OP-275, the other was AD8397), both sounded better than the CLAS+Pico Slim combo in my opinion. Somewhat a little more detailed but smooth with decent bass extensions. The AD8397 had a slight edge of treble extension over the OP-275. So I sold the OP-275 version to my friend.
* If you intend to use the Go-DAP as an iPhone charger, I'd say don't buy the Go-DAP yet. The latest firmware v1.04 was supposed to fix the iPhone 4S charging (iPhone 4 charging is fine) but what I found is that with this version, it connects/disconnects the iPhone 4S continually and it's bloody annoying. The battery will drain in approx 2 hrs.
* If you intend to use the Go-DAP only for the DAC/Amp (i.e. the Go-DAP battery is only for the DAC/Amp but not charging the iPhone), then this is fine. Whilst listening to music your iPhone battery will drain naturally and so will your Go-DAP battery for the DAC/Amp. It's approximately 7-8 hrs of continuous music listening.
I highlighted the charging as a very big thing. To me, if you're after a product that you buy and just use and forget about upgrades, this charging is a -VERY- big show stopper and recommend you to hold off the Go-DAP at least until they improve the firmware. I live only 10 km away from Venturecraft's office so I can drive and get them to upgrade once they come out with a new version. You don't and it'll be a hassle for you to ship back 'n forth through a proxy such as myself since Venturecraft isn't selling these products overseas officially.