When you talk about "calibrating" a monitor for print purposes, the word should always be set in quotation marks to denote a slight sarcasm. Here is a brief rundown of the myth of monitor "calibration" based on my experiences and training over almost two decades working in visual arts.
Monitors generally operate in RGB or Additive Color Mode. That is to say, as more color is
added, the screen approaches white. Printers generally work in CMYK or Subtractive Color Mode, which is the exact opposite. That is to say, as more color is
removed, the print approaches white. The gamut of color on even a mediocre monitor is exponentially larger than the color gamut available from even the most advanced printer. Add to that what is widely referred to in the print industry as
The Cyan Problem (a molecular issue that, while having been improved on over the past decade or so, still causes color consistency variances), and you can see the problem "calibration" poses.
Go to any high-end photography or graphics studio and you'll see that the test-printing phase of any project, especially on reproductions of paintings and other high-end art, quickly turns into a game of revision, educated guessing, mathematical calculations, and artistic judgment calls. By the time a final color profile is arrived at, there's usually a mountain of prints on the floor ready for the dumpster and -- despite having gotten remarkably close -- the end product still isn't anyone's idea of perfect. In the end, it's about knowing your gear, understanding the numbers related to color correction and grading, and being able to analyze those factors as correctly as possible.
That color channel "info" window in Photoshop, along with histograms and other values are there for a reason. A good colormaster can tell you if a skin tone will print correctly based on the numeric values of the color channels and the slope of a histogram. He'll also know things like the dot gain of his medium and the chromaticity of the monitor he's using in reference to everything else. The bottom line is because exact calibration between a monitor and a printer is, at this point in the history of technology, impossible.
I'm not saying there's no value in having a good, truish monitor and to adjust it well. But some of the nonsense products I see aimed at exploiting people's ignorance when it comes to this issue make me shake my head. In the end, you need a deeper understanding of what's really happening digitally, physically, and mechanically. That's worth more than any gadget or overpriced piece of gear.