First time I've heard of this. In my experience you get what you pay for, especially for equipment calibration. So if you want to take the plunge, just be sure you can return it if you're not happy.
The thing with with printer calibration is you're at the mercy of 1) the accuracy of your scanning instrument and 2) the quality/quantity of your target patches. Using a scanner, you'll be making icc profiles based on corrections of a corrected target. It's like post processing a jpg file from a P&S camera, if you know what I mean...
I would recommend you get a SpyderPrint, I think it's a bit cheaper than the Colormunki. Or better, get an X-rite i1 and use good quality refill inks. Believe me, the cost of the i1 is peanuts compared to the money you'll save on ink.