The only HK I own is a USP 40 that I purchased back in 1994. Though I like the pistol, in terms of examining the three main elements involved in the making of it (like the manufacture of most every other kind of hard good), design, material and workmanship; I find little to merit the relative high cost of it, or that of most HK products or most any other "high end", mass-produced firearm (SIG comes to mind) for that matter.
There are other factors that have to do with the cost of making a product and the cost of selling it, of course; to mention a few: country of origin (which often determines the cost of labor), liability insurance, overseas shipping, import/export fees, advertising budget, research/development costs, volume of sales, marketing research, distributor/dealer markups and/or markdowns, etc. But just in terms of design, material and workmanship; when I lay my HK or SIG (Models 220 and 226) pistol next to my CZ 85 or Beretta 92 pistol (or any Glock or Springfield XD pistol, for that matter), I'm sorry, I just don't see the justification for the hundreds of dollars of difference in price between them.
We are fortunate to live in a democratic, capitalistic society. If HK (or SIG) can sell pistols that are "over-priced" and people are willing to buy them, well, I say, "More power to them!" There are plenty of choices out there, from Hi-Points to Korths, and the market will continue to dictate availability and costs; supply and demand.
So, to answer the op's question: "Are HK pistols worth the money?"-the answer to me is, some people seem to think so and I guess, in the end, that's all that really counts.